Comment by frumplestlatz

10 days ago

I think can still do it, 30 years after I last had to. The trauma of debugging sendmail m4 config issues for hours while the company e-mail remained dysfunctional has permanently etched it into my mind.

  EHLO example.com
  MAIL FROM:<foo@example.com>
  RCPT TO:<bar@example.com>
  DATA
  Subject: Hello, World

  I have crawled through the depths of hell to deliver unto you this message.
  .

Wietse Venema saved us all.

3 comments

frumplestlatz

Reply
eqvinox  10 days ago

I haven't worked at sendmail or even anything e-mail related, and I can do that… just enough e-mail fixing as side work. Let's call it sysadmin calluses.

What made me stumble recently was having to talk LMTP to fix a mailman setup. Cheeky fuckers changed EHLO into LHLO for LMTP. (To avoid any mixups between the protocols, which is fair.)

Izkata  10 days ago

From and To should be repeated below DATA, those are the actual email headers. And From at least doesn't need to match MAIL FROM.

  • nedt  9 days ago

    Also TO doesn't need to match. When you send to a group of BCC the envelope To has to specify the exact recipient, but the DATA doesn't. Similar with the envelope From and the one in the DATA - also useful to control bounces or who gets a reply.

    Yeah I know the protocol and can do that manual, because I had to debug it often enough.