Now that we have ruled out the server and the port 25 block possibility,
the only remaining concern is your security software. Which third party
security software are you running? Some of them can cause intermittent
problems with Windows Mail. As a minimum, email scanning in the
antivirus should be turned off, although that may not be sufficient to
eliminate all bad effects. In a worst case scenario, your antivirus may
need to be uninstalled/reinstalled or replaced.
As an alternative to replacing your antivirus, consider upgrading to
Windows Live Mail, because it is less prone to suffering bad effects from
overly intrusive antivirus programs:
http://download.live.com/wlmail
Gary VanderMolen, Microsoft MVP (Mail)
"HJ" wrote in message
We called tech support of Concepts ICT. Their is no problem with their
servers, they say that they do not block anything and suggested that maybe an
update of our firewall causes this problem. I have no idea how I can find out
if that is correct and how ik can solve it.
Our internet connection is obtained from Concepts ICT, so the SMTP-server is
the same as the internetserver.
Circumstances? It's a private, home computer, not in a professional network
or so.
Hope you can tell me what I can try to do to solve it.