550-5.7.1 rate of unsolicited mail originating from your IP address

Recently we ran into a problem with one of our clients, who is having a 550-5.7.1 rate of unsolicited mail originating from your IP address as an error message when sending emails. We recently discussed How To Fix ‘550 Permanent Failure For One Or More Recipients’ and How To: Email Blacklist Removal. But today we will discuss 550-5.7.1 rate of unsolicited mail originating from your IP address, this error was originating when our client was sending email to Gmail addresses. Let see how we can debug and fix this error.

If doing this is too much for you, you can sign up with us and let our experts do this for you. Contact us to get started. We also help our customers with email problems.

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IP Listed on Spam Monitor

Gmail uses services of various spam monitors to check if IP is involved in any bad practices. And it turns out that our client IP was listed in the SPAMHAUS monitor. Thus Google was simply denying our mails. You can follow our Email Blacklist removal article to fix this issue.

Once your IP is removed from the spam monitors list, you will be good to send emails again.

If doing this is too much for you, you can sign up with us and let our experts do this for you. Contact us to get started. We also help our customers with email problems.

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inet_protocols = all

We managed to get our client IP removed from the spam monitor, but emails were still not going through. Once we dug deeper it turns out IPv6 of the server was also on the spam monitor blacklist and postfix was using IPv6 to send emails, thus ending up being rejected. In this case, you can follow a similar procedure and get your IPv6 removed from the spam monitor.

Or you can configure postfix to only use ipv4 protocol. Open /etc/postfix/main.cf in any editor and change inet_protocols = all to inet_protocols = ipv4. Now postfix will send emails through your IPv4 address only, which you have already cleaned in the last step. Finally restart postfix:

systemctl restart postfix

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smtp_bind_address

In case you are listed on various spam monitors (as some old tenant of the IP did some serious spam), you can assign or request a new IP address from your hosting provider and configure the IP on your server. Then you can use smtp_bind_address = 192.168.100.1 to make sure postfix is using your new IP address to send emails. Also, make sure that your new IP was also clean.

Finally restart postfix:

systemctl restart postfix

Note: Replace 192.168.100.1 in the above example with your new assigned IP address from your provider.

If doing this is too much for you, you can sign up with us and let our experts do this for you. Contact us to get started. We also help our customers with email problems.