Help Please.. Distribute Password Authentication error

[mudflap]

My boss is using his network at home to check his mail here.
We have a pop3 account setup so he can do that.
Everything was ok till yesterday. Nothing has changed on our end.

When he tries to send mail he gets this error.

Unable to log onto server using distributed password authentication. Server repsonse. The Auth protocol exchange was cancelled by the client.

Help@@

 

[sghouse]

did your boss change isp? some isp won't let you check third party mail via their network.