At 13:38 10-03-2008, James E. Pratt wrote:
No. "Possible mail loss" is really the correct term. Just because I have
no backup MX, it does not mean I will lose mail.... (Mail loss can, and
usually is caused by many more issues than just no backup/secondary MX).
Yes.
At 14:20 10-03-2008, Bob Proulx wrote:
Loss of mail cannot result solely from a primary MX being offline.
See comment about "possible".
If you believe that it can then let me ask a related but different
question. Does your mail server ever return a 4xx code such as:
- out of disk space / insufficient system storage
- dns temporarily unavailable / domain service not available
- service not available
- mailbox not available
- user quota exceeded
- too many simultaneous connections
- other
Yes.
If the mta does ever return such a code then (for the sake of
argument) the same potential for mail loss exists. If you believe
that this causes loss then you would want to ensure that none of these
conditions can ever happen. Of course this is impossible due to
practical limits.
In general, we seek to minimize the impact within practical
limits. I have seen cases when a backup MX is useful but I won't
call it a general rule as it can be more of a problem than it is worth.
Regards,
-sm
