Since I installed Skype last week at work (we use it for in-office communication) I have been receiving an error in Skype when I try and send a message which manifests itself as a little rotating "waiting" circle next to the messages I am trying to send (similar to the Win7 busy cursor) and the failure of the recipient to receive my message.
Some people have said that messages usually go through within a 10min delay but, as I said, this has been going on for a full week now and none of the messages I attempted to send have gone through. Any idea on why this would happen or how to fix it? The only "answers" I have seen online have been condescending replies of make sure both users are online when you try and send a message :) which is not helpful at all.
Best Answer
You likely have a firewall issue. Skype needs a relatively open firewall as it works on a peer to peer basis and uses random ports. It works best with UpNP on the firewall, but I wouldn't enable it on a corporate network. It does seem to be able to pass and use IP addresses in the private IP ranges (10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16).
Personally, I would choose a tool like Jabber for in-house messaging.