[lug] [ot] MX backup partners

[Jeffrey Siegal]

David Anselmi wrote:
> Presumably your servers aren't down for days at a time.  So when they 
> are down mail delivery should be retried and get through when they come 
> back up.  I've gotten messages that say "couldn't deliver in 4 hours, 
> I'll keep trying for 5 days" for mail I've sent.
> 
> Let's see what my exim setup says...  It will try for up to 4 days.

There are a significant number of mail servers that will bounce after 1 
day, though 4 days is much more common.