cyrus + postfix + lmtpd questions

[Simon Matter]

> I just want to get this straight. Please, someone clarify his to me.
> Consider Cyrus and Postifx runing on different servers and having to
> communicate with each other through lmtp.
>
> 1)
> Here´s the line we all know from cyrus.conf that is gonna bring lmtp
> listening on tcp:
>
> lmtp          cmd="/usr/local/cyrus/bin/lmtpd" listen="lmtp" prefork=1
> maxchild=100
>
> Is that enough on the cyrus side ?

That look okay, but see below...

>
> 2)
> posfix's main.cf :
>
> mailbox_transport = inet:[1.2.3.4]:24

Looks also okay.

>
> 3)
> On some previous reply someone wrote about adding the following to
> relay_domains :
>
> example.com     lmtp:unix:public/lmtp    # for a local LMTP socket
> example.com     inet:[1.2.3.4]:24        # for a remote LMTP socket
>
> and then to extend transport_maps:
>
> transport_maps=hash:/etc/postfix/transports,hash:/etc/postfix/relay_domains.
>
> Cant figure out why this is necesary.

Well, using a simple mailbox_transport like shown in 2) is the easiest
configuration. Of course you can have very complex postfix configs for
example with complicated transport maps but you don't have to make it
complex if your environment doesn't enforce it.

>
> 4)
> And last but not least. How postfix authenticates in anyway so Cyrus ????

The question is how you want to communicate. In my case I was using a
local trusted network between postfix and cyrus server so I did the
easiest thing which is running lmtpd without authentication and configure
TCP wrapper to accept only connections from the postfix host. Like so:

In /etc/cyrus.conf I had lmtpd listening preauthenticated:

  lmtp          cmd="lmtpd -a" listen="lmtp" prefork=1

In /etc/hosts.deny on the cyrus host I had:

# Allow only specific hosts to send mail via LMTP
lmtp: ALL EXCEPT mailhub.domain.tld

Regards,
Simon