Right! Here are my quick 'manual' instructions based on previous posts in this thread (thanks given).

BTW, I gained about 22 Mb of Device memory after I purged email. Check in Control Panel, memory, Device details, before and after to see what you gain.

How to really delete the mail once it is deleted in Modest.

1. Clean out all folders from email, especially inbox
2. Close email application
3. Open xTerm
4. cd ~/.modest/cache/mail/pop/your_pop_mail_account/cache
5. Delete all the folders (two character names) in here with rm * -rf

I tried to make a command that runs this in osso statusbar app as follows:
rm ~/.modest/cache/mail/pop/my_mail_account/cache/* -rf

BUT it will not delete the folders. However, if I type the same command at the prompt it will delete the folders. Is this a permissions problem? Can I add something to the SINGLE command line to get past this problem? If not what is the simplest automated (ie a couple of taps) way to run this command. I actually have two accounts to clean up so a combination 'script' would be helpful.

Thanks for any input.