Inbox is full message

[JohnBenham]

I copied everything on Thunderbird from old computer to new computer. When I ask Thunderbird to get the mail, I get the following message:
"The folder Inbox is full, and can't hold anymore messages. To make room for more messages, delete any old or unwanted mail and compact the folder."
The Inbox is not full, I have compacted - same message.
Set up a new Inbox, completely empty, same message.

[DanRaisch]

The error may be referring to the server inbox folder. How is the account set up in Thunderbird, as POP or IMAP? Find out using menu path Tools->Account Settings->Server Settings->Server Type at the top right of the dialogue.

[JohnBenham]

It is a Yahoo bizmail account, it is a POP account. I can send, but can't receive.

[JohnBenham]

Also I can get my mail fine through the Yahoo webmail, just can't get mail to download to Thunderbird.

[DanRaisch]

First, backup your Profile ( http://kb.mozillazine.org/Profile_backup )

Create a new sub-folder under Local Folders. Move all of the messages currently in your Inbox to that new subfolder.

Confirm that you have made the recommended backup of your Profile.

Close Thunderbird and navigate to the \Mail sub-folder of your Profile folder. Delete both the file Inbox.msf and the file Inbox with no extension.

Restart Thunderbird and you should find a new, empty Inbox folder in place. Copy any messages you MUST have in your Inbox from the sub-folder created above to the Inbox. Compact the Inbox after those messages are copied in.

The "Real Fix" entry in this article -- http://kb.mozillazine.org/Compacting_folders#Real_fix also describes this process.

[JohnBenham]

Did all that, still get same message.

[DanRaisch]

How many messages are currently in the Inbox folder and what is the size of the file Inbox (with no file name extension) in the TB profile folder? http://kb.mozillazine.org/Profile_folder_-_Thunderbird

[JohnBenham]

The Inbox is empty, and the size shows as "0 KB" in the profile.

[JohnBenham]

Also I have uninstalled & reinstalled a couple of times - makes no difference, get same message.

[DanRaisch]

Have you checked the account through a browser to see how many messages are in the Inbox folder there?

[JohnBenham]

I don't have an exact count, but it would be thousands - that Inbox on Yahoo has mail for 2015, 2016 & 2017 in it. But that is not the problem - my office computer is still downloading messages to Thunderbird with no problem. I am only having the problem on this new computer.

[DanRaisch]

What security software are you running on the new computer?

[JohnBenham]

Windows Defender