The buildd account needs to be able to send and receive email. This page has some configuration ideas if the stock email solution does not work for your situation.

?Anchor(uucp)

uucp over ssh

Sometimes the solution to a problem such as routing email is to go old school. You can deliver email using uucp over ssh. Hopefully someone will document something a little newer, but for now, this works.

Install uucp on both the client and server apt-get install uucp. You can setup both the client and the server to transfer mail on demand or by polling. This faq is going to cover push/push (both machines act as clients and servers). This works pretty well for buildds because they usually already have a working ssh client and server.

Client

You will need to generate a password-less ssh key for uucp.

sudo -u uucp ssh-keygen

Replace $server with the name of the mail server (I usually use the common name). Replace $client with the name of the mail client (this is like a user account). Replace $password with some password (i.e., makepasswd).

Think of this as what username ($client) and $password to use when contacting $server.

/etc/uucp/call:
$server $client $password

Tell uucp to use ssh.

/etc/uucp/port:
port sshport
type pipe
command /usr/bin/ssh -x -o batchmode=yes $server

/etc/uucp/sys:
system $server
call-login *
call-password *
time any
address $server
port sshport
protocol t
remote-send /var/spool/uucppublic
remote-receive /var/spool/uucppublic

Optionally map the common name you are using for the server to the fully qualified domain name.

/var/spool/uucp/.ssh/config:
Host $server
    Hostname $server.example.com

Server

$server, $client, and $password should match as appropriate from the client.

/etc/uucp/passwd:
$client $password

Allow the client to use the system.

/etc/uucp/sys:
system $client
time any
port tcp
protocol t
remote-send /var/spool/uucppublic
remote-receive /var/spool/uucppublic
commands        rmail rnews rbsmtp rsmtp cbsmtp rcsmtp rgsmtp

You will need /var/spool/uucp/.ssh/id_rsa.pub from the client.

/var/spool/uucp/.ssh/authorized_keys:
command="/usr/lib/uucp/uucico -l" ssh-rsa uucp_public_key uucp@client

Preparation and Testing

 working through here 

On the client you should su uucp and ssh to $server to make sure the key works. You'll get a uucp prompt.

sudo -u uucp ssh $server

You'll want a cronjob that calls "/usr/lib/uucp/uucico -C -S$server" periodically.

You can also setup your mta to make that call whenever mail is pending if you'd prefer. Something about

I believe. If you're using postfix.

And I think that's about it. I'm happy to help debug if needed.