Author: Marco Wessel Date: To: exim-users Subject: Re: [exim] how can exim 4.54 check for valid 'non-local' users when
acting as a MX gateway for remote uucp sites?
On Mar 18, 2007, at 6:11 AM, Jeff Lasman wrote:
> For a long time now our dedicated server clients have been asking
> us to
> run backup mx for them. The reason we haven't agreed to do so is
> because I've not found an easy way around the problem of callouts not
> being available when the primary mx server is offline.
>
> I can think of a way to tackle this: creating a file of usernames in
> real time on their servers, and copying it over to our backup mx
> server
> at an agreed-upon interval. I just haven't wanted to go through the
> trouble.
>
> Has anyone come up with any better ideas?
It depends a bit on what you want to achieve with this, I suppose. If
you want to never accept an e-mail to an address that doesn't exist,
then I suppose such a list is really the only option.
If you simply want to avoid a situation where your secondary refuses
email because the primary is unavailable (which would be sortof
counterproductive), then how about the defer_ok option? That would
make the verification pass if the callout didn't work out because of,
for instance, the primary box being down. This is what I use on my
secondary.
