> because I did not know if it was safe to do so. For example, I would
> never consider launching both Exim and Sendmail on the same machine,
> even if listening on different ports. Is it really is safe to do this,
> and the two instances will not interfere with each other? Do they share
> the same queue? If so, perhaps one wants to double the time interval
The MTAs use different queue directories.
It is safe and okay to have multiple MTAs installed at one time.
For example, this is frequently done when someone migrates from one MTA to
another. Even after the new MTA is handling port 25, the old MTA may still
be used (for days) so it can continue to handle its queued email.
The *BSDs include a simple sendmail wrapper so the admin can quickly
switch between MTAs.
Jeremy C. Reed
http://www.bsdnewsletter.com/
