from(1)
NAME
from − identifies sender of mail
SYNTAX
from [ −f mailbox ] [ −s sender ]
DESCRIPTION
The from command prints out the mail header lines in a mailbox file to show you who has send mail to you. The −f option causes from to examine the mail header lines in your mbox or a specified file. If the −s option is given, then only headers for mail sent by a specified sender are printed.
FILES
/usr/spool/mail/*