Intermittent mail receiving

[Nick]

A very odd experience with our email.....

We are running a small office network of 8 XP client PC's and 2003 SBS
server. We are not using Exchange at all, but retrieving all email via pop3
on the client PC's using Outlook. The same email accounts are being received
on each PC.
Just a few days ago we noticed that connections to a particular pop3 mail
server were failing on all PC's. We checked with our ISP, and no problems
were found with them. Strangely, our parent company based 100 miles away, and
using the same email accounts, and same ISP, were receiving their mail ok.
We also have other pop3 accounts using other mail servers on the same PC's,
and they are receiving mail ok.
So having checked our local settings (firewall\server etc) we found no
apparent problems. The only thing that corrected the issue, was to reboot the
router, and then all email retrieval was restored, but only for about 2
hours. After which the very same problem occurred again.
So we changed the router over to another one, but again the same problem
occurs with sporadic mail retrieval. Only rebooting the router fixes the
problem, until 1 to 2 hours again.
As mentioned, other email accounts are fine during the "problem phase", and
our parent company has had no issues with the exact same email accounts. The
company hosting the mail servers can find no problems their end.
All outgoing mail is ok, and connection to the Internet is always online.

Would anybody be able to point us in the right direction, or have had a
similar problem?
Any help would be appreciated.

Thanks

Nick

 

[Kathleen Orland]

Sounds like either a routing issue on the router end, you might want to
compare the router settings to the one that your parent company uses, or it
could be a difference in the port number that you're using for POP3.

 

[Nick]

Hi, thanks for the reply

Regarding the routers, nothing was changed at all within the router before
the problem occured, and as mentioned, we did try another router, but still
had the same problem.
Again no ports were changed either, and still using port 110

In some ways, it may make more sense if it didn't work at all, rather than
intermittently.

 

[Kathleen Orland]

I know what you mean. I had this issue at one of my locations where 50% of
the time it worked. Turned out to be a routing issue, there were entries in
the routing table that weren't needed. Once I deleted them, everything ran
100%.

Have you tried using POP3s on port 995? This is an SSL secured channel.
You'll have to check the SSL box.

 

[Nick]

Hi,

I will try port 995, and see if that helps.

I'll post back with the result!

Thanks again

 

[Nick]

:
Well Unfortunately changing the port did not help.
We also changed our external IP address to static, and still the problem
occurs.

 

[Carmel]

Give Wireshark a try:

http://www.wireshark.org/

 

[Nick]

Hi Thanks for the reply

Have downloaded the software, but having never used it, will have to study
the instructions.
As of now, we cannot connect at all to the pop3 server, even after rebooting
the router. All other accounts are still accessable, and still our parent
company is able to retrieve their mail (same A\C'\)


Very weird!!