5 Jul
2005
5 Jul
'05
11:28 p.m.
In message <Pine.WNT.4.63.0507052219510.5600@jvc>, Todd Vierling writes:
The default recommendation I give anyone these days is to use no secondaries, and let the sender's mail server queue it up, as that's the fastest implementation path. As a second stage, and only if the expertise and time is available, then a backup MX with some sort of recipient validation at SMTP time can be implemented.
The usual justification for a secondary MX is when the MX servers have some sort of special access to the ultimate recipients -- non-SMTP mail delivery, firewalls that they are privileged to pass, etc. --Steven M. Bellovin, http://www.cs.columbia.edu/~smb