cannot send mail from webmail

[kompsol]

I can receive email, but cannot send through mail.kompsol.com. I am using Thunderbird 2.

Nor can I send through webmail.

I receive the following error when trying to send mail through webmail:

Requested action not taken: mailbox unavailable
550 Verification failed for kompsol@kompsol.com
No Such User Here
Sender verify failed

However, I cannot find kompsol@kompsol.com anywhere.

Please help.

[xpguide5]

Look, sometimes mail servers have problems. There's nothing wrong with Thunderbird. First download all the messages from the server(if you need them). Then delete the email account from CPanel. Then Recreate your account. Your problem should be solved.
:thefingerfor Thunderbird!

[kompsol]

I have webmail working! Entirely my fault, was using cPanel login name instead of full email address.

However still cannot send mail through Thunderbird. Have submitted a ticket.

[alid1712]

recheck the server configuration, the security option and the port no.