Fix 454 4.7.1 Relay access denied in Postfix mail server (2024)

454 4.7.1 <[emailprotected]>: Relay access denied

This is a commonly seen email failure error by web hosts, website owners and server owners who run Postfix mail server. 454error usually happens while sending to and receiving from external domains.

In our role as Support Engineersfor web hosting companies, we handle manysuch mail errors and fix them. Here, we’ll see what causes“454 4.7.1 Relay access denied” error and how we fix it.

See how we help web hosting companies

What causes“454 4.7.1 Relay access denied” inPostfix servers

In mail delivery process, a mail client such as Outlook, Squirrelmail, etc. is used by the sender to send an email. The mail client connects to the sender’s mail server and attempts to deliver the mail to the recipient.

The recipient can be within the same mail server or in any external mail server. But most mail server require the mail account has to authenticate itself correctly, inorder to connect to it to send mails.

Error 454 is shown in the email logs and bounce message to users,usually when they send, forward or receive mails in Postfix mail servers. There are 2 main causes for this error.

  1. If the mail is attempted to send to an external mail server without proper authentication, the sending mail server will reject the mail with the error“454 4.7.1 Relay access denied”.
  2. This error message is alsoseen due to improper configuration settings of Postfix, such as relaying and recipient settings.
Jan 22 10:25:14 user postfix/smtpd[2257]: NOQUEUE: reject: RCPT from unknown[***.***.***.***]: 454 4.7.1 <[emailprotected]>: Relay access denied; from=<[emailprotected]> to=<[emailprotected]> proto=ESMTP helo=<S>

Fix 454 4.7.1 Relay access denied in Postfix mail server (1)

Email delivery process

Here, we’ll see how to fix the error“454 4.7.1 Relay access denied” that users get while using Postfix servers for email delivery.

1. How to fix “454 4.7.1” in mail clients –Outlook, Squirrelmail, Thunderbird and Roundcube

Unless specifically excluded from authenticating to SMTP mail server by adding the IPs to the trusted network, Postfix does not allow anyone to relay through the mail server.

Incorrect settings in the email client can cause mail delivery to fail, when the mail account tried to send a mail to an external domain from a Postfix server, without proper authentication.

So the first thing we do when users report 454 error is to check and confirm why the error happened in that server. Checking the mail logs, bounce message and confirming with other email clients help to pinpoint if the issue is with the mail client or server settings.

While Outlook and Thunderbird are user specific email clients and have to be configured by individual users, webmail such as Squirrelmail and Roundcube are installed and configured server wide.

If any configuration mistake happens in the installation process of 3rd party softwaresuch as Roundcube and Squirrelmail, no user from the server would be able to send mails using these webmail clients.

[ You don’t have to lose your sleep over server errors.]

How to fix “454 4.7.1 Relay access denied” in Roundcube and Squirrelmail

Roundcube has a configuration file ‘config.inc.php’, which is used for the SMTP configuration settings. If the settings provided in this section go wrong during the setup, it will give 454 error.

In Squirrelmail, the configuration file is ‘config.php’ and is configured using thePerl script‘conf.pl’. We’ve seen that webhosts who havenot configured it correctly, have users facing error 454 while sending mails.

At Bobcares, our Web Support Specialists have expertise configuring 3rd party software such as Roundcube and Squirrelmail for our customers who are web hosts.

The parameterswe configure for smooth SMTP functioning are:

  1. SMTP server for outgoing messages.
  2. SMTP authentication settings for users.
  3. TLS/SSL settings for secure email delivery.
  4. SMTP port for incoming and outgoing mails.

Once the configuration of Roundcube or Squirrelmail or other webmail clients are properly done, users can send emails without any errors.

[Use your time to build your business. We’ll take care of your servers.Hire Our server experts to resolve and prevent server issues.]

How to fix “454 4.7.1 Relay access denied”inThunderbird, Outlook Express and Microsoft Outlook

In cases where we notice that the issue is not a server wide one, but specific to the user account, it is obvious that the error has happened due to incorrect email client settings of that user.

Some of the commonly used email clients areOutlook Express, Microsoft Outlook, Thunderbird and so on. The settings for SMTP authentication, SMTP server and security varies in each mail client.

We provide the end users with the step by step details to configure their email clients, which prevents email delivery failures with the error“454 4.7.1 Relay access denied”.

Fix 454 4.7.1 Relay access denied in Postfix mail server (2)

Mail client configuration settings for SMTP

2. How to fix “454 4.7.1” error inPostfix servers

Many webhosts, especially the ones who have Plesk control panels in their servers, use Postfix as the mail server. These servers mostly have Dovecot configured for POP and IMAP services.

If we notice from the email logs that all the users in the server are getting“454 4.7.1 Relay access denied” error while sending to and receiving mails from external domains using all mail clients, we confirm that the issue is related to Postfix server.

[ You don’t have to lose your sleep over server errors.]

Postfix configuration can have errors in two sections:

1. Errors in the configuration file

The configuration file for Postfix is ‘/etc/postfix/main.cf’ and it contains the list of networks (mynetworks), who can relay through the mail server without authenticating.

The config file also has sectionsfor relaying and authenticatingmails. If this config file ‘main.cf’ gets corrupted during modifications or updates or setup, it can affect email delivery.

We’ve seen cases where even a single white space in the file can mess up theconfiguration.

With years of experience handling such issues, ourexpert hosting support engineers are able to resolve the mail server errors without much downtime.

454 4.7.1 <[emailprotected]>: Relay access denied

This is a commonly seen email failure error by web hosts, website owners and server owners who run Postfix mail server. 454error usually happens while sending to and receiving from external domains.

In our role as Server Support Engineersfor web hosting companies, we handle manysuch mail errors and fix them. Here, we’ll see what causes“454 4.7.1 Relay access denied” error and how we fix it.

See how we help web hosting companies

What causes“454 4.7.1 Relay access denied” inPostfix servers

In mail delivery process, a mail client such as Outlook, Squirrelmail, etc. is used by the sender to send an email. The mail client connects to the sender’s mail server and attempts to deliver the mail to the recipient.

The recipient can be within the same mail server or in any external mail server. But most mail server require the mail account has to authenticate itself correctly, inorder to connect to it to send mails.

Error 454 is shown in the email logs and bounce message to users,usually when they send, forward or receive mails in Postfix mail servers. There are 2 main causes for this error.

  1. If the mail is attempted to send to an external mail server without proper authentication, the sending mail server will reject the mail with the error“454 4.7.1 Relay access denied”.
  2. This error message is alsoseen due to improper configuration settings of Postfix, such as relaying and recipient settings.
Jan 22 10:25:14 user postfix/smtpd[2257]: NOQUEUE: reject: RCPT from unknown[***.***.***.***]: 454 4.7.1 <[emailprotected]>: Relay access denied; from=<[emailprotected]> to=<[emailprotected]> proto=ESMTP helo=<S>

Fix 454 4.7.1 Relay access denied in Postfix mail server (3)

Email delivery process

Here, we’ll see how to fix the error“454 4.7.1 Relay access denied” that users get while using Postfix servers for email delivery.

1. How to fix “454 4.7.1” in mail clients –Outlook, Squirrelmail, Thunderbird and Roundcube

Unless specifically excluded from authenticating to SMTP mail server by adding the IPs to the trusted network, Postfix does not allow anyone to relay through the mail server.

Incorrect settings in the email client can cause mail delivery to fail, when the mail account tried to send a mail to an external domain from a Postfix server, without proper authentication.

So the first thing we do when users report 454 error is to check and confirm why the error happened in that server. Checking the mail logs, bounce message and confirming with other email clients help to pinpoint if the issue is with the mail client or server settings.

While Outlook and Thunderbird are user specific email clients and have to be configured by individual users, webmail such as Squirrelmail and Roundcube are installed and configured server wide.

If any configuration mistake happens in the installation process of 3rd party softwaresuch as Roundcube and Squirrelmail, no user from the server would be able to send mails using these webmail clients.

[ You don’t have to lose your sleep over server errors.]

How to fix “454 4.7.1 Relay access denied” in Roundcube and Squirrelmail

Roundcube has a configuration file ‘config.inc.php’, which is used for the SMTP configuration settings. If the settings provided in this section go wrong during the setup, it will give 454 error.

In Squirrelmail, the configuration file is ‘config.php’ and is configured using thePerl script‘conf.pl’. We’ve seen that webhosts who havenot configured it correctly, have users facing error 454 while sending mails.

At Bobcares, our Support Specialists have expertise configuring 3rd party software such as Roundcube and Squirrelmail for our customers who are web hosts.

The parameterswe configure for smooth SMTP functioning are:

  1. SMTP server for outgoing messages.
  2. SMTP authentication settings for users.
  3. TLS/SSL settings for secure email delivery.
  4. SMTP port for incoming and outgoing mails.

Once the configuration of Roundcube or Squirrelmail or other webmail clients are properly done, users can send emails without any errors.

[Use your time to build your business. We’ll take care of your servers.Hire Our server experts to resolve and prevent server issues.]

How to fix “454 4.7.1 Relay access denied”inThunderbird, Outlook Express and Microsoft Outlook

In cases where we notice that the issue is not a server wide one, but specific to the user account, it is obvious that the error has happened due to incorrect email client settings of that user.

Some of the commonly used email clients areOutlook Express, Microsoft Outlook, Thunderbird and so on. The settings for SMTP authentication, SMTP server and security varies in each mail client.

We provide the end users with the step by step details to configure their email clients, which prevents email delivery failures with the error“454 4.7.1 Relay access denied”.

Fix 454 4.7.1 Relay access denied in Postfix mail server (4)

Mail client configuration settings for SMTP

2. How to fix “454 4.7.1” error inPostfix servers

Many webhosts, especially the ones who have Plesk control panels in their servers, use Postfix as the mail server. These servers mostly have Dovecot configured for POP and IMAP services.

If we notice from the email logs that all the users in the server are getting“454 4.7.1 Relay access denied” error while sending to and receiving mails from external domains using all mail clients, we confirm that the issue is related to Postfix server.

[ You don’t have to lose your sleep over server errors.]

Postfix configuration can have errors in two sections:

1. Errors in the configuration file

The configuration file for Postfix is ‘/etc/postfix/main.cf’ and it contains the list of networks (mynetworks), who can relay through the mail server without authenticating.

The config file also has sectionsfor relaying and authenticatingmails. If this config file ‘main.cf’ gets corrupted during modifications or updates or setup, it can affect email delivery.

We’ve seen cases where even a single white space in the file can mess up theconfiguration.

With years of experience handling such issues, ourexpert support engineers are able to resolve the mail server errors without much downtime.

2. Corruption in Postfix domain lookup database

Postfix stores local domain routing details in databases for Plesk servers, and this information is looked up during mail delivery locally. If this DB gets corrupt or has missing entries, email delivery to local domains fail.

Mail service is crucial for online businesses. Web hosts need to ensure seamless mail delivery services for their customers, for sustaining theirbusiness.

Bobcares engineersthink from webhosts’ shoes, which is why we focus on resolvingemail errors in a few minutes, with our effective debugging of server logs, configuration and error messages.

In our customers’ servers, we proactively secure and audit the mail servers to avoid any issues that could affect the services. If you’d like to know how you can better support your mail users, we’d be happy to talk to you.

2. Corruption in Postfix domain lookup database

Postfix stores local domain routing details in databases for Plesk servers, and this information is looked up during mail delivery locally. If this DB gets corrupt or has missing entries, email delivery to local domains fail.

Mail service is crucial for online businesses. Web hosts need to ensure seamless mail delivery services for their customers, for sustaining theirbusiness.

Bobcares engineersthink from webhosts’ shoes, which is why we focus on resolvingemail errors in a few minutes, with our effective debugging of server logs, configuration and error messages.

In our customers’ servers, we proactively secure and audit the mail servers to avoid any issues that could affect the services. If you’d like to know how you can better support your mail users, we’d be happy to talk to you.

Fix 454 4.7.1 Relay access denied in Postfix mail server (2024)

FAQs

How do you fix a relay access denied? ›

How to fix Relay Access Denied Error in Mail.
  1. Verify Mail Server Settings and Account Credentials. ...
  2. Enable SMTP User Authentication & Secure Connection. ...
  3. Verify Email Settings with your Email Provider & Scan for Viruses. ...
  4. Check if your Mail Server or your Domain is Listed at SPAM (BLOCK) lists.

Can't send mail all recipients were rejected 454 4.7 1? ›

454 4.7. 1 Relay Access Denied – This error code is observed inside server logs when the recipient server is temporarily incapable to receive emails. In such a case, another attempt to send mail will take place later.

What does it mean when email says Relay Access Denied? ›

This means that you are trying to send the mail from an outgoing mail server (SMTP) other than the one that is associated to your mailbox, and that the outgoing mail server does not allow such an action.

How do I check my postfix config? ›

Check configuration

Run the postfix check command. It should output anything that you might have done wrong in a configuration file. To see all of your configs, type postconf . To see how you differ from the defaults, try postconf -n .

What is Relayhost in postfix? ›

The relayhost setting forces the Postfix SMTP to send all remote messages to the specified mail server instead of trying to deliver them directly to their destination. In the relayhost setting, the " [ " and " ] " prevent the Postfix SMTP client from looking up MX (mail exchanger) records for the enclosed name.

What ports does SMTP use? ›

Which port should you use for SMTP? Ports 25, 465, 587, or 2525 for SMTP have all been considered standard SMTP ports at some point, but only 587 or 2525 really should be considered for modern use.

What does authenticated SMTP access mean? ›

The Authenticated SMTP product allows emails to be sent out from a domain through our outgoing mail servers. Due to the authentication method it uses, it ensures that emails can only be sent from a domain if the sender is using a valid username and password associated with that domain.

How do I fix 550 relaying denied? ›

It's likely that the email server isn't correctly set up to receive and relay messages from your organization. To fix this issue, forward this non-delivery report (NDR) to your email admin. The sender's message was routed to an email server outside Microsoft 365 that returned an error that it can't relay the message.

What is my Gmail outgoing mail server? ›

The outgoing SMTP server, smtp.gmail.com , requires TLS. Use port 465 , or port 587 if your client begins with plain text before issuing the STARTTLS command.

Can't send mail all recipients were rejected 550 5.7 1 relaying denied? ›

This error message means the recipient email address you entered is invalid or doesn't exist in the destination domain. It happens either because of email address typos or due to a misconfiguration of the recipient's server.

Can't send mail all recipients were rejected 451? ›

The error "451 Temporary local problem" comes from the actual mail server you are connecting to. Typically, 451 errors are due to the receiving server rejecting your email. This can happen for a number of reasons but most likely is due to the recipients server being overloaded with messages.

How do I fix sender not authorized for Relay? ›

It's likely that the email server isn't correctly set up to receive and relay messages from your organization. To fix this issue, forward this non-delivery report (NDR) to your email admin.

How do I fix 554 5.7 1 VI blocked message due to spam content in the message? ›

That error message means the message has been rejected by the recipient's domain (the receiving end), and so, your outgoing SMTP server failed to deliver it. This is not something you can fix from your end as the sender.

How do I fix error 554 in Gmail? ›

The issue is caused by the local computer sending the email, and not by the server or email server having the wrong the time. To resolve the issue: Double-click the time on the right-bottom corner of the computer. Check for the correct day, month and time.

How do I troubleshoot postfix? ›

Postfix Debugging Howto
  1. Look for obvious signs of trouble.
  2. Debugging Postfix from inside.
  3. Try turning off chroot operation in master.cf.
  4. Verbose logging for specific SMTP connections.
  5. Record the SMTP session with a network sniffer.
  6. Making Postfix daemon programs more verbose.
  7. Manually tracing a Postfix daemon process.

How do I connect to postfix? ›

  1. Step 1: Prepare Google. Open a web browser and log into your Google account. ...
  2. Step 2: Install Postfix. Before you can configure the mail client, you need to install it. ...
  3. Step 3: Set up Gmail authentication. ...
  4. Step 4: Get Postfix moving. ...
  5. Step 5: Set up the password file. ...
  6. Step 6: Get Postfix grooving. ...
  7. Step 7: Test it.
9 Aug 2018

Is postfix a SMTP server? ›

Introduction. The Postfix SMTP server receives mail from the network and is exposed to the big bad world of junk email and viruses. This document introduces the built-in and external methods that control what SMTP mail Postfix will accept, what mistakes to avoid, and how to test your configuration.

How do I relay mail in postfix? ›

Configuring the Relay Server
  1. Using a text editor, open the /etc/postfix/main.cf file.
  2. Update the relayhost configuration with your external SMTP relay host. ...
  3. Add the end of the file, add the example file's parameters to enable authentication and save the changes you made to your main.cf file.
30 May 2014

What is difference between SMTP and postfix? ›

postfix/smtpd - This is typically the SMTP daemon process for handling incoming mail and routing to the appropriate internal location. postfix/smtp - This is typically the SMTP daemon process for delivering mail out to the world.

What is Relay in email? ›

Email relay is the process of transmitting an email message from one server to another. In the picture above, the local post offices would be the SMTP servers and the email transfer that happens between them is what we call 'relaying'.

Is port 587 a SSL? ›

msa (port 587) Ports 465 and 587 are intended for email client to email server communication - sending out email using SMTP protocol. SSL encryption is started automatically before any SMTP level communication. It is almost like standard SMTP port.

How do I find my SMTP settings? ›

Outlook for PC

In Outlook, click File. Then navigate to Account Settings > Account Settings. On the Email tab, double-click on the account you want to connect to HubSpot. Below Server Information, you can find your incoming mail server (IMAP) and outgoing mail server (SMTP) names.

Is port 587 TLS or SSL? ›

Port 587 is often used to encrypt SMTP messages using STARTTLS, which allows the email client to establish secure connections by requesting that the mail server upgrade the connection through TLS.

Does SMTP relay require authentication? ›

SMTP sender authentication requires an account name and password for the destination SMTP server. The account name you use must be an account on the relay host SMTP server to which a specific Domino® server routes messages.

Can I use SMTP without authentication? ›

Senders need to authenticate and prove that they have a valid account. If they don't, the server will reject their request. All of this is possible with SMTP authentication, also known as SMTP AUTH.

How do I authenticate my email server? ›

How to Authenticate Your Email in 5 Steps
  1. Use consistent sender addresses. Be consistent with the from addresses and friendly from names you use. ...
  2. Authenticate your IP addresses with SPF. ...
  3. Configure DKIM signatures for your messages. ...
  4. Protect your domain with DMARC authentication. ...
  5. Prepare for BIMI.
22 Feb 2021

How do you fix 550 5.1 1 The email account that you tried to reach does not exist? ›

Solution 1: Confirm the recipient's email address

It sounds too simple, but the wrong email address is the most common issue that causes 5.1. x errors. Check for correct spelling and send the message again if you find an error in the email address. To resend the message in Outlook, see Resend an email message.

How do you fix 550 high risk of spam? ›

Common Solutions To This Error
  1. Limit The Number of Emails Sent Per Hour/Per Day.
  2. Ensure The Contents Of Your Email Don't Read As Spam.
  3. Verify That Your DNS Security Settings Are Properly Setup.

What does 550 relay not permitted mean? ›

If users trying to send you emails receive a “550 relay not permitted” error, it likely means that your mail server has received the message but is not configured to work with your domain. If your mail server processes every email coming its way, you would have the so-called open relay setup.

Does Gmail allow SMTP relay? ›

If your organization uses Microsoft Exchange or another SMTP email server, you can set up SMTP relay to route outgoing mail through Google. Use SMTP relay service options to: Filter messages for spam and viruses before they reach external recipients. Apply email security and advanced Gmail settings to outgoing messages.

Is Gmail POP or IMAP? ›

Gmail supports IMAP clients that use IMAP4rev1, including: Microsoft Outlook. Windows Mail. Apple Mail.

How do I find my SMTP username and password? ›

How can I find out my SMTP User Name and SMTP Password?
  1. Log in to your account in the Secure SMTP Control Panel.
  2. From the top menu select 'SMTP Accounts'.
  3. Select the required SMTP account from the list, and click the 'Edit' button.
  4. On the 'Edit SMTP Account' page you can change your SMTP User Name and SMTP password.

How do I enable SMTP authentication? ›

Enable SMTP AUTH for specific mailboxes
  1. Open the Microsoft 365 admin center and go to Users > Active users.
  2. Select the user, and in the flyout that appears, click Mail.
  3. In the Email apps section, click Manage email apps.
  4. Verify the Authenticated SMTP setting: unchecked = disabled, checked = enabled.
5 days ago

What does 550 permanent failure for one or more recipients mean? ›

Server IP Blacklisted by Recipient's Mail Server

So, if you get a “550 permanent failure for one or more recipients” error, the first thing you have to do is to confirm whether your server IP has been blacklisted or not. Moreover, there are lots of tools available that can help you with spam blacklist checks.

How do I enable SMTP in Gmail? ›

Set up the app or device with the Gmail SMTP server

On your device or in the app, enter smtp.gmail.com as the server address. In the Port field, enter one of the following numbers: If you're using SSL, enter 465. If you're using TLS, enter 587.

How do you fix 451 relay not permitted? ›

Resolve Exchange Server 451 Error
  1. First check the port numbers 53 for DNS and 25 for SMTP protocol and also check the settings of Firewall.
  2. Open the Exchange Management Console and click on Edge Transport Server.
  3. Select the properties and go to internal DNS Lookups.
  4. Set the settings to default.
8 Apr 2021

Why is my email rejecting emails? ›

The server was down. The message was too large for the recipient's inbox. The recipient's inbox was full. The recipient's settings do not allow for an email from the sender.

What is 451 relay not permitted? ›

451 You have exceeded your messaging limits

When a sender tries to send an email, a connection to his/her mail server is established. Most mail servers have limited the number of connections allowable for an mail account. This connection limit is set to combat abuse or spamming of the mail server.

How do I enable SMTP authentication in my mail client cPanel? ›

How to Set Up SMTP in cPanel
  1. Click the “Create” button.
  2. On the next page, select a domain, a username, and a password. ...
  3. On this page, you will find the username and the URL and SMTP port number of the outgoing server. ...
  4. We strongly recommend using the more secure SSL/TLS details rather than the insecure Non-SSL settings.
3 Sept 2020

Can't send mail all recipients were rejected 454 4.7 1? ›

454 4.7. 1 Relay Access Denied – This error code is observed inside server logs when the recipient server is temporarily incapable to receive emails. In such a case, another attempt to send mail will take place later.

How do I fix Relay Access Denied? ›

How to fix Relay Access Denied Error in Mail.
  1. Verify Mail Server Settings and Account Credentials. ...
  2. Enable SMTP User Authentication & Secure Connection. ...
  3. Verify Email Settings with your Email Provider & Scan for Viruses. ...
  4. Check if your Mail Server or your Domain is Listed at SPAM (BLOCK) lists.

How do I fix message blocked due to spam content in the message? ›

Possible reason for this issue might be the recipient who receives your email might blocked the email from your domain or they would have made some setting change on their email account. To resolve this issue you can inform the recipient to add your email address as a “Safe Sender” in their email account settings.

How do I fix SMTP Error 554? ›

Solution - Here's How To Resolve It

Invalid Recipient Address - Check if the email address(es) you are attempting to send the emails to is valid and if there are no spelling mistakes. Blocklisted IP Address - The user must remove their IP Address or domain from public blocklists.

What does 554 Access Denied mean? ›

It means that the server is not allowing an email to be sent to another mail server. The most common causes of this error are: The sender did not authenticate to the outgoing mail server. The recipients server has determined the senders server to be a source of spam, or that it had failed security checks.

What is 554 message not allowed? ›

You'll receive an SMTP error or failed delivery message that includes "554 Message not allowed" when the content of a message you're trying to send violates Yahoo Mail policies. Content that violates policies includes; objectionable links, malicious attachments, or bad header information.

How do I fix error 554 in Gmail? ›

The issue is caused by the local computer sending the email, and not by the server or email server having the wrong the time. To resolve the issue: Double-click the time on the right-bottom corner of the computer. Check for the correct day, month and time.

What does 550 relay not permitted mean? ›

If users trying to send you emails receive a “550 relay not permitted” error, it likely means that your mail server has received the message but is not configured to work with your domain. If your mail server processes every email coming its way, you would have the so-called open relay setup.

What does 451 relay not permitted mean? ›

451. Recipient Temporarily Unavailable. The Sender's IP address has been placed on the block list due to too many invalid connections. The sender's mail server must retry the connection.

What is Smtpd_relay_restrictions? ›

This is called allowlisting; the smtpd_relay_restrictions example above allows mail from local networks, and from SASL authenticated clients, but otherwise rejects mail to arbitrary destinations. The table below summarizes the purpose of each SMTP access restriction list.

How do I fix SMTP Error 554? ›

Solution - Here's How To Resolve It

Invalid Recipient Address - Check if the email address(es) you are attempting to send the emails to is valid and if there are no spelling mistakes. Blocklisted IP Address - The user must remove their IP Address or domain from public blocklists.

What is 554 transaction failed? ›

Email errors can be frustrating to deal with, especially when error codes like “SMTP 554 transaction failed” are not clear to the sender. The 554 error indicates that the email didn't go through. Simply put, the email transaction between the sender and receiver's email was unsuccessful.

What is a SMTP error? ›

An SMTP error, or Delivery Status Notification (DSN), indicates that an email could not be delivered, either due to a temporary or permanent problem.

How do I fix SMTP 550 error? ›

How do I fix a 550 error?
  1. Check for email address typos. ...
  2. Check whether the email IP is blacklisted. ...
  3. Try sending the email after some time. ...
  4. Try changing your outgoing mail port. ...
  5. Check whether IP filtering is enabled. ...
  6. Enable SMTP authentication. ...
  7. Troubleshoot the SSL method. ...
  8. Contact your ISP.
19 May 2020

Is currently not 550 permitted to relay through this server? ›

1.1) or Server error: 550 relay not permitted, authentication required / Relay not allowed The most common cause is that authentication is missing in the outgoing mail settings. With outgoing mail, your e-mail address / login and corresponding password are also required.

How do you fix 550 5.1 1 The email account that you tried to reach does not exist? ›

Solution 1: Confirm the recipient's email address

It sounds too simple, but the wrong email address is the most common issue that causes 5.1. x errors. Check for correct spelling and send the message again if you find an error in the email address. To resend the message in Outlook, see Resend an email message.

How do I bypass error 451? ›

To bypass the Error 451 message, you can use tactics that hide your browsing location, such as a VPN, proxy, or Tor Browser. In some cases, changing your DNS provider to Cloudflare or accessing the HTTPS version of the site might also work.

How do you fix 451 relay not permitted? ›

Resolve Exchange Server 451 Error
  1. First check the port numbers 53 for DNS and 25 for SMTP protocol and also check the settings of Firewall.
  2. Open the Exchange Management Console and click on Edge Transport Server.
  3. Select the properties and go to internal DNS Lookups.
  4. Set the settings to default.
8 Apr 2021

What does SMTP error 451 mean? ›

SMTP error 451 indicates when the user exceeds the limits set on the email server for sending emails. The email server will not allow the user to send more emails than the limits set on the email server; these limits are set as daily or hourly limits to restrict abusive behavior.

How do I relay a postfix email? ›

Configuring the Relay Server
  1. Using a text editor, open the /etc/postfix/main.cf file.
  2. Update the relayhost configuration with your external SMTP relay host. ...
  3. Add the end of the file, add the example file's parameters to enable authentication and save the changes you made to your main.cf file.
30 May 2014

How do I connect to Postfix SMTP? ›

How to configure Postfix to use an External SMTP Server
  1. Install Postfix. If you've already installed Postfix, skip to Step 2. ...
  2. Configure Postfix. Edit the Postfix configuration file. ...
  3. Create Password and DB Files. Create the sasl_passwd file which will store our credentials. ...
  4. Sign Certificate. ...
  5. Send a Test Mail. ...
  6. 24 replies.
7 Feb 2021

What ports does postfix use? ›

Notes: On the linux server, by default, postfix is running and listens on SMTP port 25. Postfix is used to send server related messages to the root user.

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