I suggest you upload an image of this.

Please tell us: what OS you are using what version of Thunderbird are you using Are you talking about a Pop or Imap account ?

Just had a thought...Does that message mention something like 'Compact' to save disk space ? If yes, that means doing some basic maintenance on files.

When you delete or move emails, those emails get 'marked as deleted' because they are not required in that file any more, but they are hidden from your view. In reality they are still in the mbox file. Compacting means removing all those old 'marked as deleted' emails, thus cleaning up file, saving space and helping to maintian a healthy file - reduces risk of corruption. Info on compacting :

• https://support.mozilla.org/en-US/kb/compacting-folders

I cannot get the notice back. I just the e-mail just does not message now indicating that I have one. I still get the sound but no visual on it.

Chas.