James Price wrote: > I am having an issue with recipient callout verifications.
>
> I maintain a border mx which sits in front of my hosting servers which are
> ultimately the destination for the mail. The destination server is a
> qmail/plesk setup and my border mx is exim 4.66.
>
> In my ACL I have:
> require verify = recipient/callout=10s,defer_ok
>
> Now here comes the weird part...
>
> If I send an email to somenonexistantuser@??? from the Exim
> server, ie the gateway, the callout returns a failure as its supposed to.
> If I send an email from any number of real world mail servers, in this case
> my work smtp server, I do not get a failure from the Exim server, Exim
> routes the mail to the destination which in turn bounces saying no mailbox
> exists.
If the final internal destination sends a bounce, that means it accepted
the mail address even if it was a wrong one, so no callout could verify
that it indeed exists as the server accepts everything.
To use a callout, the remote server (whether it is internal or not)
should not accept non existent users in the first place. In your case it
seems it does accept mail to non existent users.
