I am unable to send email to external addresses from my mail client. When I try to send a message to an external address, I get the following error from Postfix:
NOQUEUE: reject: RCPT from domain.net[174.51.xxx.xx]: 554 5.7.1 <user@somewhere.external.com>: Relay access denied;
What is causing this and how do I fix it?
There are 2 fixes to this issue:
If you are using a version of Postfix prior to 2.10.0, make sure you have the following lines in your Postfix main.cf file:
smtpd_recipient_restrictions =
permit_mynetworks
permit_sasl_authenticated
defer_unauth_destination
If you are using Postfix 2.10.0 or higher, make sure you have the following lines in your Postfix main.cf file:
smtpd_relay_restrictions =
permit_mynetworks
permit_sasl_authenticated
defer_unauth_destination
NOTE: After postfix 2.10.0, `smtpd_relay_restrictions` should be used instead of `smtpd_recipient_restrictions`. (`smtpd_recipient_restrictions` should now only be used for spam restrictions).