[comp.mail.sendmail] UNIX "From " line

murray@motto.UUCP (Murray S. Kucherawy) (04/23/91)

I know there are two "from" lines in UNIX mail, but I'm not sure if my
sendmail is properly configured to handle them.

I'm not convinced that sendmail is passing "from" lines out right.  It
rewrites "From: murray" to "From: motto!murray", but "From murray" (the
line without the colon) stays as-is when it goes out.  Is this correct?
If not, where do I place a rewrite rule to fix it?

=============================== Murray S. Kucherawy ==========================
Motorola Canada, Ltd.     Communications Division, Toronto      [on work term]
University of Waterloo, Ontario, Canada               2B Math/Computer Science
Internet: murray@motto.UUCP (work)       mskucherawy@watmath.UWaterloo.ca (UW) 
UUCP:     uunet!utai!lsuc!motto!murray   uunet!watmath!mskucherawy

rickert@mp.cs.niu.edu (Neil Rickert) (04/24/91)

In article <79@motto.UUCP> murray@motto.UUCP (Murray S. Kucherawy) writes:
>I know there are two "from" lines in UNIX mail, but I'm not sure if my
>sendmail is properly configured to handle them.
>
>I'm not convinced that sendmail is passing "from" lines out right.  It
>rewrites "From: murray" to "From: motto!murray", but "From murray" (the
>line without the colon) stays as-is when it goes out.  Is this correct?
>If not, where do I place a rewrite rule to fix it?

 Actually, sendmail would prefer to have nothing to do with the 'From '
line, which is not a valid RFC822 header.  In particular, the 'From '
line is NEVER passed through as is.

 What really happens is that when 'sendmail' receives a message beginning
with a 'From ' line, it silently tosses the 'From ' line into the bit bucket,
since it is not a valid header.

 However, on output, it will create a new 'From ' line, if needed, depending
on mailer flags.  In that case is uses the internal value of $g to create
the line.  (More accurately it uses the definition of the From line from
within sendmail.cf).  Typically the 'prog' mailer and the 'uucp' mailer call
for the creation of the unix 'From ' line.

 Most likely you are being confused by the format of the From line.  Whereas
it might read

From motto!murray date and time stuff

 when sent to the 'prog' mailer, for the uucp mailer it will usually read

From murray date and time stuff remote from motto

 That 'remote from motto' on the end of the line is the logical equivalent
of the 'motto!' prefix on the address, except that some older implementations
of uucp/rmail will only accept the 'remote from host' version.

-- 
=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=
  Neil W. Rickert, Computer Science               <rickert@cs.niu.edu>
  Northern Illinois Univ.
  DeKalb, IL 60115                                   +1-815-753-6940