Change the "From:" address in Unix "mail"

In my version of mail ( Debian linux 4.0 ) the following options work for controlling the source / reply addresses

• the -a switch, for additional headers to apply, supplying a From: header on the command line that will be appended to the outgoing mail header
• the $REPLYTO environment variable specifies a Reply-To: header

so the following sequence

export [email protected]
mail -aFrom:[email protected] -s 'Testing'

The result, in my mail clients, is a mail from [email protected], which any replies to will default to [email protected]

NB: Mac OS users: you don't have -a , but you do have $REPLYTO

NB(2): CentOS users, many commenters have added that you need to use -r not -a

NB(3): This answer is at least ten years old(1), please bear that in mind when you're coming in from Google.

mail -s "$(echo -e "This is the subject\nFrom: Paula <[email protected]>\n
Reply-to: [email protected]\nContent-Type: text/html\n")" 
[email protected] < htmlFileMessage.txt

the above is my solution....any extra headers can be added just after the from and before the reply to...just make sure you know your headers syntax before adding them....this worked perfectly for me.

GNU mailutils's 'mail' command doesn't let you do this (easily at least). But If you install 'heirloom-mailx', its mail command (mailx) has the '-r' option to override the default '$USER@$HOSTNAME' from field.

echo "Hello there" | mail -s "testing" -r [email protected] [email protected]

Works for 'mailx' but not 'mail'.

$ ls -l /usr/bin/mail
lrwxrwxrwx 1 root root 22 2010-12-23 08:33 /usr/bin/mail -> /etc/alternatives/mail
$ ls -l /etc/alternatives/mail
lrwxrwxrwx 1 root root 23 2010-12-23 08:33 /etc/alternatives/mail -> /usr/bin/heirloom-mailx

On Centos 5.3 I'm able to do:

mail -s "Subject" [email protected] -- -f [email protected] < body

The double dash stops mail from parsing the -f argument and passes it along to sendmail itself.