I am using a SPAM filtering service that relays mail to my exchange
server. Mail has suddenly stopped arriving. I am able to telnet to my
public IP and create and send a mail to any recipient. The SPAM
filtering service can telnet to Exchange and do the same, except from
their outgoing mail server. In other words, the tech can get to
exchange from xxx.xxx.xxx.246 but not from xxx.xxx.xxx.247, which
happens to be the outgoing mail server address. I can see him pass thru
my router in the log from .246 but .247 creates no entry. ISP still
claims not to be blocking. Further research, I found out that the .247
address was blacklisted by McFadden Associates ( http://www.yqcomputer.com/ ).
Filter service had them removed ASAP. What I need to do is find out
where in the routing between SPAM filter svc and ISP port 25 is being
blocked, so I can try to find out who owns and why they are blocking
mail at all. Is there some kind of tool or utility that can do
something like tracert but on a specific port???