Although the To: part is logged fine when mail is delivered, the From:
line is virtually never logged as mail is accepted.
I have been unable to work out why it was on the rare occasion when it was.
I am also seeing this problem with different version of Sendmail and RH. I
have seen it with RH7.0 and Sendmail 8.9.3 and 8.12.2.
If I stop Sendmail and stop syslog and then start syslog and then start
sendmail it will then log correctly again -- with the "from" line.
The sendmail people say it is a bug in syslog (from sendmail newsgroup): the
likely cause is a broken syslog() function in the C library. Restarting the
sendmail daemon should "fix" it until next time you restart the syslog
If you see a from=<> line in your /var/log/maillog, thats normal.
It is not imperative that sendmail shows the from= email in maillog.
Sometimes the smtp server that sends the email to sendmail, does not include
that line. It can be omited.