MX Record Configuration

[Barry Finkel]

Kevin Darcy replied to a posting:

>There's nothing magical about the first label of the name, in SMTP 
>terms. The only thing that really matters in terms of SMTP failover is 
>the preference value. If your box -- whatever it's called -- has a 
>preference of 5 and your ISP's box -- whatever it's called -- has a 
>preference of 10, then mail will be delivered to your box, if possible, 
>and only if it is not possible will sending MTAs fail over to your ISP's 
>server.

When I last looked at spam statistics on our backup mail relay box,
I found that 25% of the mail to that box was legitimate mail, and
75% was spam.  I know that our primary mail relay box was not
unavailable 25% of the time, so there are mailers on the Internet
that do not follow the rules in the MX RFC.  I did not have time to
look at some of the mail to try to determine what mail software
delivered the mail to the higher preference MX host.
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Barry S. Finkel
Computing and Information Systems Division
Argonne National Laboratory          Phone:    +1 (630) 252-7277
9700 South Cass Avenue               Facsimile:+1 (630) 252-4601
Building 222, Room D209              Internet: BSFinkel at anl.gov
Argonne, IL   60439-4828             IBMMAIL:  I1004994