Smarthost Failover - WAS RE: [Mimedefang] SMTP mailertable qu estion

[Cormack, Ken]

> "Cormack, Ken" wrote:
>> First, the only references I have found in any documentation,
>> including the O'Reilly sendmail book (the "bat book") and the
>> cf/README file included in the sendmail source tree, only show the
>> use of a colon in SMART_HOST, in the context of
>> 
>>         "MAILER:hostname"
>> 
>> I would assume that any attempt to use hostnames here such as
>> "host1.domain.com:host2.domain.com" (as opposed to litteral IP
>> addresses) would be interperated by sendmail in this fashion
>
>At a guess, enclosing hostnames in []'s would eliminate that- if you're
>relaying mail for something, for instance, you may want to explicitly
>specify a destination hostname rather than allowing sendmail to try an
>MX lookup on that name.

Enclosing the hostnames in brackets would not work.  The function of the
brackets is to signify to sendmail that the enclosed entity is a litteral IP
address not requiring lookups of any kind (as opposed to a "name" of some
sort, against which MX and/or PTR lookups are needed.)  This is mentioned in
other contexts, in the sendmail litterature.

Ken