Hector Martin

Oh my. I've entered into a community that's running email servers for a specific purpose and it seems as if some of them don't know how / why email works. This tweet brought to you by some of them saying you needed to allow relaying for email to local recipients.

One of them was also checking to see if the Secure Submission (a.k.a. "submissions") was available on TCP port 465, by connecting and looking for the "250 " string. S/he wasn't seeing it on any system. I'm guessing because they weren't starting a TLS connection.

Also, the greeting banner will respond with "220 " and only give the "250 " after the client HELO's or EHLO's.

They didn't sort a list of mail servers based on MX priority.

One of them also didn't know the difference between a delay notification and a bounce.

Today's example: Running Postfix locally (and complaining about it) to provide the /usr/sbin/sendmail command instead of configuring the client to use an SMTP server. All of which passes through ToR.

I do that pretty commonly. It's easier and more flexible to run a local postfix with a really dumb smarthost-style config, then basically ~all software that wants to send email magically works and you get queuing and other goodies.

It's part of my standard non-email server setup, often with a config to rewrite anything@<service domain or hostname> to postmaster, so that daemon-generated emails all get funneled to a known destination.