Cannot Delete Files From Deleted Folder

I'm running OL2007 on a Vista Ultimate machine. All has been well for the past year, but lately, I have run into the problem described below. It seems to happen most often when I address an e-mail to multiple recipients. It shows stuck in the outbox, although it appears that most of the time it does get sent. I often get a message to the effect that "Sent Items folder is full, delete some of the messages" (it doesn't have any more messages in it than usual, I purge them regularly).

Then, I find I can't delete the offending file. I get a simple "Folder is full" message. Also, I cannot delete any files from my deledted folder I now have 2090 files stuck in my deleted files, 6 emails stuck in my outbox. I cannot rely on sending any email from my home computer and now am relying on my lotus notes at work. I have contaced Dell - no help. I have observed all information in the discussion groups, The Intel IT people who are my neighbors have ried to address this. I am one of many experienceing this problem - even Intel staff have the same uncorrectable problem. Could Microsoft work on this issue ASAP as it is forcing me to use other email addresses and doesn't allow me to continue to work form home....