[plug] Sendmail return address mangling?

[Colin 't Hart]

Hi all,

Can someone give me a basic rundown on why one would want
sendmail (or any other MTA) to mangle the return addresses
of emails?

My uninformed opinion would be to leave the return address as what
the use put on the email, just like Australia Post leaves your
return address intact when you write it on the back of your envelope.

Or does the email vs snail mail comparison not extend so far?

Do firewalls affect the picture? What about when the mail server is
inside the firewall? The firewall also needs to act as a mail server
in this case, right?

Any insights greatly appreciated.

Cheers,

Colin

PS Why I ask? Where I work the sendmail.cf is setup this way, AFAIK