I have several concerns with Droid's e-mail capability:
1) Today and for the last few days, several times, the e-mail client hung in Loading Messages.... mode and nothing short of powering down would get it to stop. Today, I discovered that I missed e-mail for a few hours for this reason. And worse, after rebooting the Droid, I still could not retrieve the missing mail that my desktop could retrieve.
2) Not being able to create folders is a huge shortcoming.
3) Not being able to cut and paste from one e-mail to another is another huge shortcoming. I use e-mail templates to respond to clients quickly by copying and pasting and editing and on the Droid this is impossible to accomplish.
4) I purchased Documents To Go and still, after a software update, I can not view most .pdf files sent to me. Some are viewable. The unviewable ones are always viewable on my desktop pc.
5) A large business critical spreadsheet will not load into Documents To Go. It starts and then freezes. Dataviz support is useless as they blame the Droid for every problem.
Please, please, someone produce a reasonably capable e-mail program for this otherwise wonderful phone or I, and I suspect many others will have to sell it and go back to what works.