Author: Suresh Ramasubramanian Date: To: Andreas Metzler CC: exim-users Subject: Re: [Exim] "550 cannot route to sender address" from remote smtp.
now what?
Andreas Metzler writes on 10/12/2003 9:37 PM:
> lists.s.o needs either an A or an MX record (or a CNAME resolving to
> an A or an MX record.).
Please don't use a CNAME for mail delivery (at least, don't point an MX
to a CNAME) - that is horribly broken.
The basic reason for this statement is this part of RFC 974 -
> Note that the algorithm to delete irrelevant RRs breaks if LOCAL has
> a alias and the alias is listed in the MX records for REMOTE. (E.g.
> REMOTE has an MX of ALIAS, where ALIAS has a CNAME of LOCAL). This
> can be avoided if aliases are never used in the data section of MX
> RRs.
