Here is an alternative to mail for the MAC. Don't get me wrong I love Mail, but this one does a lot more that Mail, but one feature that I didn't like was the ability to add stationary - try it out and see if you like it...

Official Web Site:  http://www.postbox-inc.com/

Postbox 2 is first class email software that puts you in the driver’s seat. Stay on task, find information quickly and act, not react.

* Account Groups

Postbox 2 now supports Unified Inboxes, which lets you combine messages from multiple accounts into one Inbox.

Accounts can also be organized into Account Groups, so you can keep your work and personal messages separate.

Add as many accounts to a group as desired. Then, select a group to get a unified view for messages within the group.

* Focus Pane

Postbox 2 introduces the Focus Pane, a new feature that lets you break your Inbox (and workload) into smaller, more manageable chunks.

Easily organize the Focus Pane by your highest work priorities — such as projects, clients or events — then focus on these messages without losing track of what's happening elsewhere.

* Summarized Replies

Postbox’s Conversation View simplifies message viewing, and now, “Summarize Mode” extends these benefits to message Replies and Forwards.

Summarize provides a clean and beautifully formatted who-said-what-when email that lets message recipients jump into discussions with more clarity, context and insight.

* Quick Reply

Quick Reply lets you reply to a message without the need to open a separate compose window, which is perfect for short, snappy responses such as "I'll see you at eight," or simply "thanks!"

And it all happens inline within a message or conversation, so that you can get right back to what you were doing.

System Requirements:

Mac OS X 10.5 and Snow Leopard
Intel Core processor family

Link to the manual:  http://www.postbox-inc.com/quickstart

-- PLEASE SEED --

I'm looking for BusyCal from the same co., iConCalPro but haven't found it yet....