Sendmail masquerading configuration

[Ted Mittelstaedt]

> -----Original Message-----
> From: Ruben de Groot [mailto:mail25 at bzerk.org]
> Sent: Monday, February 07, 2005 6:55 AM
> To: Ted Mittelstaedt
> Cc: Ian Moore; freebsd-questions at freebsd.org
> Subject: Re: Sendmail masquerading configuration
> 
> 
> On Sun, Feb 06, 2005 at 02:28:17AM -0800, Ted Mittelstaedt typed:
> > 
> > 
> > > -----Original Message-----
> > > From: owner-freebsd-questions at freebsd.org
> > > [mailto:owner-freebsd-questions at freebsd.org]On Behalf Of Ian Moore
> > > Sent: Sunday, February 06, 2005 2:07 AM
> > > To: freebsd-questions at freebsd.org
> > > Subject: Sendmail masquerading configuration
> > > 
> > > 
> > > Hi,
> > > I'm hoping someone can help me with this.
> > > 
> > > I want to make sendmail (on a 5.3-Release server) leave the 
> > > host name out of 
> > > the sender address when sending mail from that machine.
> > > I.E. mail from root currently has a sender address of 
> > > root at myhost.foo.bar, I 
> > > want it to be root at foo.bar instead.
> > > 
> > 
> > Not possible, I think, as I recall masquerading only works on 
> > users not in the T macro. (ie: Trusted Users)  root is
> > most definitely in this macro.
> 
> Actually, I believe it's the EXPOSED_USERS macro, and it can be
> adjusted; e.g. in sendmail.cf:
> 
> C{E}root
> 
> just remove the root user from this line. In conjunction with a 
> MASQUERADE_AS macro, this will allow root to send email coming from
> your domain without your hostname.

If you do this then lots of messages generated by the system will
suddenly start generating (at best):

X-Authentication-Warning: myhost.foo.bar: root set sender to 
someuser using -f

It also makes it harder to troubleshoot when someone external to
your system is sending bogus junk to you.

And while it's not applicable now, with older versions of sendmail
this would definitely break all your scripts that used e-mail.

Use of the -f flag is what he needs to do.

Ted