Cannot access mailbox

The system will prompt me incorrect username/password. GVC VPN tunnel can be built successfully , but after 2-3 hours later , I can access mailbox smoothly. Everything seems OK . nothing changed.

I have confirmed that the username and password I typed in are all correct.

 

Using Outlook Express?

This might be seem too simple an answer...
But your problem might just be your ISP having hiccups. (problems)
Depending how long this has been happening.
I remember having similar problems with my ISP during their "maintenance" periods.

Also get in contact with them to confirm your E-mail settings.

 

just today , i can not access my mailbox again, GVC VPN tunnel can not be built , but webmail works ok .and sometime, nothing works! , or sometime , VPN tunnel can be built , but can not access exchange server via outlook , only webmail works ,SSL-VPN prompt an incorrect usernama or password again,i have tried two internet connections from two different ISP. but till now i can only access my mailbox via webmail.