I have reverted back to Ritlabs The Bat email client having previously used Thunderbird. When I left The Bat its HTML support was very limited and this has now been rectified in this release. Given its quicker searching of emails and faster template based email composition I had to move back over. For novice users there will be too many options but it makes life so much easier than any other client I have ever come across.
If you recieve hundreds of emails a week then this is the client for you. Correspondents names and greetings are automatically placed according to your templates making replies a doddle.
There is also a nice discount offered for student users so there is no excuse!