Random Undeliverables/Bounces

[Mike H]

Hello all,

Recently we've been getting seemingly random bounced emails; someone you may
be able to email in the morning is generating bounces in the afternoon. I've
tried checking out a few things:

1) Our mailserver is not blacklisted.
2) The connection is stable, so far as I can tell.
3) The bounces are not domain-specific.

What could be causing this?

 

[F. H. Muffman]

Recently we've been getting seemingly random bounced emails; someone you
may
be able to email in the morning is generating bounces in the afternoon.
I've
tried checking out a few things:

1) Our mailserver is not blacklisted.
2) The connection is stable, so far as I can tell.
3) The bounces are not domain-specific.

What could be causing this?

What does the failed delivery status notification say as to why it couldn't
deliver? Is it always the same?
What type of mail server? Is it configured to send to a particular mail
host, or is it using DNS to determine the proper host to send mal on a
domain by domain basis?