on 800x600 it has some horizontal scrolling.

perhaps they could be re-written for different screen sizes;

I read somewhere that a signature should not be longer than 3 lines. True/False?

Also, I see that you are composing e-mail with HTML enabled. Using a plain text signature doesn't look a bit weird then? Maybe it would be a good idea to address this question and also, how do I produce a formatted signature?

I've read about a bug which bugs many people, that the signature always gets positioned at the very end of a message, below all quoted text. Some would like to have it at the end of your text, before any remaining quoted text (for business usage especially). Maybe you should address this too.

When I was a beginner, I was really confused by the 2 dashes preceding a signature. IIRC, Outlook doesn't do that. But you should mention that this is the standard way to display a signature, at least in the plain text format. Wondering however if this still makes sense if the mail message is formatted with HTML...

When I first introduced Netscape Mail to my girlfriend, she was wondering how she could get the names from her address book and tried to click in the side where you define To, CC, BCC etc... I had to tell her that she just should type anything like last name, first name, nick or beginning of the e-mail address, provided all this information is in the address book. At that time I showed her that all recipients of her sent messages get automatically added to her personal address book.

She was first also a little bit confused about the way to add multiple recipients. In Outlook she has been using at the office for 3 years you add all recipients in one line. Here you can too, if you add a semicolon after each address. But it's easier to hit ENTER and write every recipient in a new line. For each one you can then change the way to send (Oh this guy should only get a CC) no need to cut it from the TO field and move it to the CC, like you have to do in Outlook.

Just a few comments that come to my mind :) As you can see, sometimes even sending a mail can raise a lot of questions. I was surprized myself ;)

Great introduction to Thunderbird. Hopefully following articles will cover subjects like handling rules and junk mail. To me, these are probably the most important part of any email application.

The Compose window has new buttons.

We have online a Thunderbird tutorial which, while still in the works, is pretty comprehensive: http://www.FreeEmailTutorials.com/mozillaThunderbird/

HTH!