Browser

Question 1 - Firefox does have an email client called Thunderbird. I am not quite sure what you mean by facility...

Question 2 - This link will answer your other question....yes you can, here is how

http://kb.mozillazine.org/Migrate_from_Mozilla_Suite_or_Netscape_to_Thunderbird

The Mozilla SeaMonkey project is very similar to what you are used to with Netscape 7.

http://www.seamonkey-project.org/

SeaMonkey does have a built in composer just like Netscape.

Otherwise, as in the first answer, you will need to install both Firefox and Thunderbird to replace Netscape.

Chas