footer appending

[Revina]

i am starting in learn c programming. my system (freebsd 3.3) 
is running webserver with nice working sqwebmail 1.2.1.
i'd like to add "footer" (signature look like) to "body" of 
all outgoing message, which appended to "body" when 
send only, so not save to "draft".
which file should be modified, and/or what to do?
any help would be greatly appreciated...thx.

i'm sorry with my english :)
regards,
revina