[Mimedefang] redundancy in mimedefang

[Cor Bosman]

> Considering this situation:
> Two installations of mimedefang configured as incoming mx servers for a
> mail domain, configured to relay mail to some internal mail server.
> M1 and M2 are their names.
> 
> Fault Tolerance:
> M1 is down, then all mail is routed through M2.
> Based on clients point to the next mail server on the mx record.
> If M1 dies anything on the ramdisk spool is lost.
> How to prevent this?
> How to prevent any mail from every being lost, even if 1 of the cluster
> dies?
> Set up seperate mail spools? A disk spool and ramdisk spool?
> Synchronize the ramdisk to disk?
> 
> Ramdisk is being used for performance requirements.

If you use a ramdisk for the minedefang spool then mail wont get lost.
If a server reboots while MD is handling mail it doesnt return anything
to the remote host. They'll then keep the email and try again later.

Dont use a ramdisk for any sendmail spool though.

Cor