Re: [exim] Sender callouts not checking MX?

Gregg Berkholtz wrote:
> After making the jump from Exim 3.35 to 4.60, my callouts are behaving
> differently than expected. As they no longer appear to be checking the
> domains MX, and instead perform callouts either back to the connecting
> host, or hostname in the email address.

With 'verify = sender/callout', exim does check the host named in the MX
record. I had the same impression that the sending host rather than the
MX records are used for the callout when tracing a problem last week,
but it turned out to definitely use the MXs.

Check out the docs for the options your using on the callout. I guess
your problem might be there.

You can disable the callout cache by setting the timeout to 1 minute to
force actual callouts being made. Then you can telnet into the SMTP port
of the mail server and type SMTP commands manually to have a sending
address verified. If you telnet from an address outside your LAN, exim
will make a callout and print out an error message stating the IP that
was questioned when making the callout. You will find that it questions
the address obtained from the MX record.


GH