Your mailbox is over the high water mark. Please delete some messages from your mailbox!
I get this message often even though I delte email empty trash and compact sent folder. at the moment I only have 21 emails in my inbox. I also keep getting error messages saying my email cannot be saved or it won't send.
ყველა პასუხი (1)
Do you have a POP3 or IMAP account?
I suspect it's POP3 and you only remove messages from your local store and keep them on the server… You can setup Thunderbird to also remove messages from the server when you remove them locally as follows: Go to the menu Tools -> Account Settings -> [account] -> Server Settings and check both Leave messages on server and Until I delete them. You can also choose to automatically remove messages from the server after a couple of days.
Now you have to login to your ISP's webmail interface to remove the messages that are still online, but are deleted locally. Just open a browser and login to your ISP's webmail to check which ,messages are still there and to remove them.