I added a Yahoo mail account to the Droid's combined inbox along side my work Microsoft exchange account.
You can connect to Yahoo mail for free using IMAP and this solution from mobiletech.knguyentu.com
Update: above link is broken. Settings listed at the end of this entry.
The Droid can handle up to ten email accounts in the combined inbox. They each are assigned a different vertical colored line to pick them out. You have the choice of looking at the accounts separately.
I sent photos for web deadline today for the first time today using the Exchange email. The exchange syncs up with the work account's folders and email addresses.
Large files just seem to disappear and are gone immediately without any status. I have noticed a status appears back on the email header page if you jump back fast enough.
The email interface is the same for all email accounts, so once you get comfortable, it's an easy to jump between the accounts.
The combined account gives you the choice of polling for mail from 5 to 1 hour intervals.
Manual settings to set up Yahoo Mail as IMAP in the Droid combined Inbox
Incoming server settings
IMAP server:imap.mail.yahoo.com
Port 143
Outgoing server settings
SMTP server:smtp.mobile.mail.yahoo.com
Port: 587
Check require sign-in and input your usernam/pass
"Love is not a thing to understand.
Love is not a thing to feel.
Love is not a thing to give and receive.
Love is a thing only to become
And eternally be. ."