Use the MAIL command to visit CNet's POSTOFFICE. From the postoffice, you can send mail, read your mail, verify mail (check to see if mail that you've sent is still in the addressee's inbox), and edit your personal address book.
To quickly compose a message without first going to the postoffice, use the MAIL command followed by the address(es). For example:
MAIL Ken Pletzer@1:2410/215
MAIL Ken Pletzer; Joe User; Frank Sinatra
To read your mail without first going to the postoffice, use the MR command shortcut.