You can free up even more memory on your phone by moving all of your downloaded mail and attachments to your Storage Card.
Updated for Windows Mobile 6!
01
Using the file manager in activesync, create the following folders on your Storage Card.
\MAPI
\MAPI\ATTACHMENTS
You can actually name them whatever you want, “Inbox” for example.
02
Now browse to \Windows\Messaging (SmartPhone) [...]
