[SLUG] Secondary MXes [Was: Virus scanning bounce strategy]

[Jeff Waugh <jdub@xxxxxxxxxxxxxx>]

<quote who="David Kempe">

> I have been steadily disabling secondary MXes for some time now. Its just
> a great way to attract spam - not an option when you net connection is not
> stable/permanent, but aside from that secondary MX just seems to be spam
> trap.

Random hints for interested thread-readers:

  1) If you don't control the secondary MX, it is barely better than
  useless.

  2) If your primary mail server goes down often enough or long enough that
  you think you need a secondary MX, you really need to fix your primary,
  build a cluster or outsource.

  3) If your primary mail server is on a dynamic IP address, no matter how
  "stable" you think it is, you are doomed with a capital F.

  4) It is one million times [1] more important to have stable DNS than it
  is to have a secondary MX. If your DNS server goes down, you're toast. If
  your primary mail server goes down, clients will keep the mail queued for
  a reasonable period of time. If your primary mail server goes down for
  long enough that clients will start dumping mail, see (2).

- Jeff

[1] The figure sounds outrageous, but I can prove it. [2]
[2] LSD required.

-- 
GVADEC 2004: Kristiansand, Norway                    http://2004.guadec.org/
 
                         Grind'n'wink. That is all.