HTC low on storage issue - resolved
After a lot of research I think I finally solved this issue. I used HTC mail when I first got my Hero, but this storage issue kept popping up so I deleted my hotmail account from there and started using Droid mail. But there was 85m of data that I could never get rid of and the "low storage" warning kept popping up. No matter what I deleted it kept returning for months.
I committed an entire weekend to getting to the bottom of this and once I did I wanted to post something to help those who were as frustrated as I was in trying to find an answer.
First I had to root the phone which, after a lot of research, I found a relatively easy way to do (I am college professor and a programmer from long ago, but not skilled in the droid language and too old to learn). I went to the xda developer forum and to this link:
[APP]SuperOneClick v1.5.5 (Root, Unroot, Enable Non-Market App, Get UNLOCK code) - xda-developers
Here I got info on and downloaded the Superclick app and followed the instructions for rooting the phone.
Once the phone was rooted and I had "Superuser" status, I had to downloaded the Super Manager app from the android marketplace (free app) to use its file manager and gain access to the root folders. It took me a while, by I finally found the folder which held the 85m of data left over from the HTC mail app.
Once in Super Manager, I went to the following folder(s)
File Explorer> data> >data>com.htc.android.mail>
app_mail_temp
there were several other folders there like app_temp, app_mail, files, etc.
When I went in those folder there were hundred of files with sequential numbers. I clicked them all, deleted them and ... Surprise!!! There was my 85m of data. As soon the delete was done the "low on phone storage" warning went away.
I went back to Settings>Manage applications> HTC Mail
so I could check to see if the data had actually been deleted and the data size was down to 1.9m for the HTC mail app. The reason for this, I think, is because there were other folders with files that I did not delete because I wasn't sure what they were and didn't want to go too far and screw up the phone. Until I figure that out I can live with losing 83m of data though and no more warnings (and hopefully a faster functioning phone).
So far I think this solves the problem. I don't know why HTC designed the phone to store the email data like that and making it so hard to delete, but I won't be using that app any more.
I'm satisfied to finally get to the bottom of this, although I lost a lot of sleep this weekend.
Hope this helps those who were as frustrated by this as I was.