Howto: receive mail and save attachment with fetchmail, procmail and metamail

At work I recently had to set up a solution that periodically checks a POP3 account on our M$ Exchange wannabe mailserver, and saves the attachments to some folder for further processing. As I didn't find a ready-to-go-solution for this on the web, just snippets here and there, and of course hundrets of other people asking the same, here it is.

You will need

• fetchmail
• procmail
• metamail (or uudeview, see first comment below)

In this example I'll use a POP3 account, the full mail will be backed up to ~/mail_backup, and attachments will be unpacked to ~/attachments. fetchmail also handles IMAP accounts just fine. Please refer to the fetchmail documentation.

Setting up fetchmail

First create a file $HOME/.fetchmailrc

poll my.pop3.server protocol pop3 user 'myuser' password 'mypassword' mda '/usr/bin/procmail -d %T'

 

Setting up procmail and metamail

Then we configure procmail so it forwards the messages to metamail in $HOME/.procmailrc

:0*^content-Type:{        # backup the complete mail first..        # you can leave out this part if you don't want a backup of the complete mail        :0c:        $HOME/mail_backup        # Now the actual unpacking part        #        # this is the place where the attachments will be unpacked to        METAMAIL_TMPDIR=$HOME/attachments        # forward to metamail        :0fw        | metamail -w -y -x}

Regarding metamail, we tell it to ignore any mailcap file, so it doesn't use interpreters (-w), yanking the message and save the content raw (-y) and force it in non-interactive mode (-x).

That's it about it. We are ready for testing.

Test run

Now we simply fire up fetchmail, the rest should be magic.

fetchmail -kv