[ Thanks to Rob
Kennedy for this link. ]
“In my last article I described how to receive email under Linux
using Fetchmail. This time I’m going to describe how to send
mail using (You guessed it) sendmail.“
“The MTA (Mail Transfer Agent) is not just used to receive
incoming email, it also sends email to other hosts. In case you’re
not online all the time, sendmail could connect to your ISP every
time you want to go online. But if someone would try to respond to
your email, you won’t be able to receive the email, unless your
online in the moment the email arrives. To avoid this problem, you
can rewrite the “From” address of your email. If you change the
origin of your mail to the mail address of your ISP, you can use
you standard mail address to handle all incoming/outgoing
mail.”
“Because sendmail is (still) the most used MTA, I’m going to
explain it’s configuration. The sendmail reads it’s configuration
from a highly complex file (/etc/sendmail.cf). But you don’t have
to edit this file, you can edit the simple m4 macro file
(/etc/sendmail.mc)…”