re :the techies at my server said do not update Thunderbird, so I have obeyed them.

So these 'techies' have advised you not to update TB which usually includes security and bug fixes. Not exactly the best of advise.

re; The folder Drafts is full, and can't hold any more messages. To make room for more messages, delete any old or unwanted mail and compact the folder.

This message gives detailed instructions, so have you acted upon them? You have not said if you have followed the advise in the error message. Did you right click on Local Folders 'Drafts' folder and select 'Compact' ?

Thank you, Toad-Hall.

There WAS no bug -- what creates a bug? It was working fine before!

The error message re: "full" is not detailed enough! If it is so definite that my drafts folder is full, then the details I need are:

    How many messages do I need to delete?
    If it's not one for one (number of messages), then is it size?
    If size, then tell me how many KB or MB or GB I need to delete.

Yes, I did follow the very vague instructions -- as I said in my first sentence:

     "even though I've cleaned it off considerably!"  

Here's the scenario -- it was working great for months. Then suddenly (a week or so ago), I'd get one or the other or, in sequence, both error messages specified. I'd go to the draft folder and delete old and unwanted mail. Once or twice that seemed to fix it. And logic says that, if a two-line message you're working on needs to be saved, deleting ten large messages in the folder should certainly provide the missing room, and saving capabilities (capacity) would resume. In actuality, I deleted over 100 message drafts. Now, that doesn't seem to matter.

I did NOT "compact". If I deleted 100 messages, there should be room nominally for 100 new ones. What exactly does compacting do -- physically, to the folder? Any time I've tried that before, it completely corrupts the folder or individual messages in it. I'm very leery about trying that, for the same reason I am reluctant to upgrade to a higher number of Thunderbird. If I do, I want both the compacting and the update to be completely reversible without damage.

Also, updates never really say what improvements they are adding. Tell me in the update request that Thunderbird 3.1.7 " will fix a newly discovered bug in the failure to save in-progress messages, either automatically or manually, in a local draft folder that has been reduced in size as instructed" and not that it is just an "important update".

Even when you delete messages and empty the trash, those messages do not go. They are flagged not to be displayed, but are still there. Compacting is what clears them out. http://kb.mozillazine.org/Keep_it_working_-_Thunderbird

hi plumbingfactory re :To make room for more messages, delete any old or unwanted mail and compact the folder.

When you delete a message it is 'marked as deleted'. From your point of view it goes to the 'Deleted' folder. In reality, it is still in the 'Drafts' folder taking up space, but hidden from view. This means that if you had deleted something in error, it is possible to retrieve it, which is a very useful feature. However, as it is still using space and you do not need to retrieve anything you deleted, you can completely remove all traces and regain space by compacting. Hence the error message which says not only to delete but also to compact the folder.

The same applies to all your folders.

The Drafts mbox file has emails listed one after the other in the order downloaded or created by you. 'Marked as deleted' emails will be a section amongst those emails. If a folder has any corruption (you may not be aware of the corruption), the corrupton may mean TB cannot identify the end of a deleted message, it may end up deleting good messages as well. So, it is a good idea to make periodic backups and compact on a more regular basis.

Hope this info helps explain what is going on.