🚀 go-pugleaf

I performed my own test today. My mail leaves this site with the following
From line:

From: Bill Wisner <wisner@killer.dallas.tx.us>

My first step was to find a neighbor that left my From line untouched.
I addressed a message to mit-eddie!killer!wisner and it came back with
the same From line it started with. OK. Good enough.

I then sent mail to texsun!sun!eddie.mit.edu!killer!wisner. This path
does leave two sites as possible culprits, but it's all the same company.
This message arrived looking like this:

From: Bill Wisner <texsun!wisner%killer.dallas.tx.us@Sun.COM>

Revolting. Any self-respecting mailer will think that my account is on
texsun.

killer.dallas.tx.us is completely valid and has MX records (but no A
record). It seems that Sun's idea of a 'valid host' is one that it
can find an address for. By sending my mail through Sun I pretty much
destroy any chance that I might get replies.

While we're on the subject of revolting mailer behavior, might I add
that texsun appends a CR to every line of every message it passes
through?

I think I'm going to go add "-d sun" now.