Otavio Exel writes ("[Exim] beeing an MX backup for a friend"):
...
> - define a special set of retry rules for his domain so that mail will
> sit here until his connection comes up instead of returning an error
> message;
>
> my questions are:
>
> - is this what is called an "MX backup"?
Yes, but I get the impression that his system is mostly disconnected.
You should not use MX backup for this, because it will cause all
senders to spend ages trying to connect to the primary all the time.
You should arrange for all mail to go via your machine.
Ie, list only your machine in the MX records, and use other mechanisms
to get the mail to him (like a domainlist router which uses byname to
contact his host by name rather than by MX record).
Ian.
