Autor: Tim Jackson Data: A: exim-users Assumpte: Re: [exim] Re: domain refuses all mail sent from <>, dialup
exim4/debian
Hi Marc, on Thu, 14 Oct 2004 23:21:13 -0400 you wrote:
[checking if ISPs accept null sender mail] > It would be nice to use this approach to verify potential IPSs, but in
> testing the dig on the MX followed by the telnet to port 25, it seems
> my machine is unable to telnet to port 25 of any machine outside of my
> current domain.
There's a good chance that your current ISP has blocked all outbound port
25 connections, to prevent some of the problems caused by viruses/worms
etc. I actually wish more ISPs would do this, so long as they had an "opt
out" for customers that know what they're doing.
You'll have to try from some location that doesn't have outbound port 25
blocked, or get the new ISP to give you a written agreement that they will
not indiscriminately block null sender mail.
