Set a mail folder within Microsoft Office Outlook to be watched by Digsby for new email. It would be nice to then be able to delete, move (to a user-set pre-defined Outlook folder), or mark-as-read, email messages in that folder directly from a Digsby icon, as is currently possible for Gmail.

I think that push notifications would be much more efficient than constant pulling for new email.

And would enable us to get notified automagically™ the instant new email arrives not 5 or 10 minutes later. (just like IM)

more info:

http://en.wikipedia.org/wiki/IMAP_IDLE
http://www.precentral.net/palm-pre-gmail-and-imap-pushes-imap-idle

Google has announced that Wave is in development. They have made API and protocol details available for developers. Digsby should include Google Wave integration as soon as the product/protocol has been launched, if possible.

Provide an option for the user to control whether all items in inbox are shown or just new mail. Will offer the ability for users to manage email without having to log into through browser window or email client. Should still only light up icon in systray or buddy list if new mail arrives.

The ability (checkbox?) to show an unread mail count from not only the inbox but also the labels, possibly even the spam? This feature is found in "Gmail Manager" and other similar addons in Firefox.
Even if it could just show a total from ALL labels as opposed to downloading individual every time from the Gmail server. I'm sure this would suit most people.

Ability to only show an email icon in the system tray if there are unread messages.

Ability to open a specified URL instead of an email client when clicking a message, inbox, compose etc. This is for people using webmail (that is not Gmail, Yahoo etc).

It would be good if you could set digsby as a default email client. That way any email link found on the internet (mailto:info@etc) would automatically fall into digsby. At current you can't set it as a default email client.

Digsby already has an email notification sound but how about adding the option to customize this sound for different accounts? For example: I have 2 different POP3 accounts. Account "A" is my business account. Account "B" is my personal account. I want sound "A" to play when account "A" receives a message. I want sound "B" to play when account "B" receives a message.

Instead of multiple icons that clutter up the system tray, how about one single yet intuitive icon that is shared for all pop3 accounts. A "mouse-over" pop up could tell you the status of each of your accounts.