> Hello, >
> >>what is exim exactly doing when it does a verification of the sender?
> >
> > It runs the address through the routers.
>
> ok, then its clear. I thought it would start with a DNS-lookup no matter
> which router is configured.
>
> Regards
> Marten
>
One of the first routers is usually 'dnslookup', if the domain is not
handled locally..
And Exim does check for correct DNS entries for the remote domain (MX and/or
A records)