It seems I was getting that error message because already those folders contained more than 7,000 or so emails. I am not really sure what the cutoff mark is exactly. Whereas if a folder has 3,500 messages or so it will still accept more and does not produce an error message.

So I just created new folders as needed for those folders that have thousands upon thousands of messages. Now the filing system is working quite smoothly.

With your permission I would like to keep this thread active for a short while longer, just in case anything pops up. I will circle back and mark it solved in due course....

The two new profiles both skip a line (i.e. double spaced typing) when I hit the return key. How do I set it so that it just goes down a single line?

Preferences/Composition/HTML Style, uncheck 'Use paragraph format...'.

The tags attached to the various emails did not transfer over completely. These are tags I have used for many, many years.

There used to be six numbers to designate tags and I was using 1 (red), 2 (yellow), and 6 (green).

The red and yellow tags made the transfer as they are both still represented by 1 & 2.

Now green is represented by 3 - not 6, so all my green tags are now gone. I had a few thousand of them.

Why did they reduce the number of tags from 6 to 5, and is there anyway to somehow recapture all my prior green tags that were marked by pressing the number 6 on the keyboard??

The default tags are 1-5, but you can define as many as you like. Tags are not easily transferred between profiles unless the IMAP server supports them, i.e. supports 'keywords', so that they can be synced when the messages are synced.

http://kb.mozillazine.org/Tags

Thanks so much I think we can close out this thread.

Unfortunately, I clicked on the wrong response that solved the overall issue with this post. I do not know if that can be undone. If so, I will come back and select the correct response.

Thanks again for all your help!!