You are here

email

Postfix IPv4 Only

I have a postfix SMTP relay buried deep in a network behind proxy servers, all the infrastructure [sadly] is IPv4 only. This works, yet one ends up with many log messages like:

connect to smtp.office365.com[2603:1036:304:2857::2]:587: Network is unreachable

The server attempts if IPv6 result from the DNS lookup first. So let's make postfix use IPv4 only.

postconf -e inet_protocols=ipv4

That's it! No more "unreachable" log messages.

Sequestering E-Mail

When testing applications one of the concerns is always that their actions don't effect the real-world. One aspect of that this is sending e-mail; the last thing you want is the application you are testing to send a paid-in-full customer a flurry of e-mails that he owes you a zillion dollars. A simple, and reliable, method to avoid this is to adjust the Postfix server on the host used for testing to bury all mail in a shared folder. This way:

Theme by Danetsoft and Danang Probo Sayekti inspired by Maksimer