ClearFoundation

I am using ClearOS 5.2.
I do not know if my question is due to a problem at my desktop or at my server.
On my desktop (Windows 7) I am using Thunderbird as my mailclient.
After making a new message to send, Thunderbird says:
Error saving message to the Sent items folder.
The message is sent anyway, but it is not stored...
Is that a problem of my ClearOS or a problem in Thunderbird?
How to solve that problem?

This is most likely caused by the non existence of the defined "Sent Items Folder". Check in your Thunderbird settings where one defines the "Sent Items Folder" and change it to the appropriate folder you want. You can store your sent emails on the local PC or if you are using IMAP to connect to the ClearOS you can also select the "Sent Items" imap folder to be used for storing your sent emails.