A computer on my network has Windows SP1 x64 and Skype v7.3 installed. Everything works fine except for message delivery: incoming and outgoing messages take 1-5 minutes to reach the recipient, however calls go through without issues.
I suspect there's some sort of an issue with the local network configuration. Here's what I've researched so far:
Other computers in the network don't experience the same issues, so it's probably not caused by the router configuration.
Trying to open web.skype.com fails, since the page takes too long to open.
Connecting to the network through a VPN does fix the issue
The hosts file is empty
So the question is: how can I fix/debug the issue with Skype's message delay? Is there a tool I can use to check which of Skype's connection attempts fail/take long to establish?