IPv4 only for Outgoing Emails?

[dcodesdev]

I'm currently running a Postal mail server and have encountered an issue where some of the outgoing emails are attempting to use IPv6 instead of IPv4. For my specific use case, I need Postal to only use IPv4 for all outgoing email traffic. This is because my server does not support PTR records for IPv6, and some providers reject emails without proper PTR records. These same providers accept emails sent using IPv4.

Is there a way to configure Postal to only use IPv4 to send emails?

[willpower232]

I believe this is accomplished by changing the config so the smtp_server doesn't use :: but I'm not sure. There are a few discussions around here talking about disabling ipv6 altogether on your server which, whilst not recommended, would probably do the trick.