Author: Sven Hartge Date: To: exim-users Subject: Re: [exim] stupid hosts using bogus rcpt to
Daniel Tryba <d.tryba@???> wrote: > On Wednesday 08 July 2015 17:38:55 Sven Hartge wrote: >>> But incredibly stupid, how will the sender ever know its mail isn't
>>> getting delivered to the endpoints? >> That's his problem then, not yours, isn't it? > It becomes my problem if the recipient doesn't accept the mail (even with
> recipient verification a more strict filter may reject on the enduser MTA),
> then my relays get frozen messages in the queue. Enough of these will raise
> warning/alerts and the need to find out if there is a problem in my domain.
Ah, you don't store the mail locally but forward the mail to an external
system outside of your control.
Then, of course, you are between a rock and a hard place.
But as the others said, a callout to an external system to verify a
complete mail address is dangerous and will land you on multiple
automatated blacklists.
Verifing the existance of a domain via a DNS lookup is fine of course,
but checking the localpart is bad. Please don't do this.