Do we need to configure postfix for using Google Apps gmail?

Question

Do we need to configure postfix to use Google Apps gmail account or adding the correct MX records is sufficient.

I'm trying to use Google Apps gmail account for my domain. Hosted on CentOS 6 VPS. I have 12 emails in total. One of which is for mailing list subscription using mailchimp (sending newletter).

Out of the remaining emails, one I wish to set for auto reply.

Remaining 10 are to be used with Google Apps gmail account.

So far, I was able to verify my domain with google. I've added MX records correctly as per Google's recommendations.

I am receiving bounce mail if I try to send email to that account stating that server gave a 550 5.1.1

Do I need to configure postfix for this? If yes, is there any guide or reference for this?

Answer 1

if you want all your emails to be handled by gmail, you should not need to configure an SMTP-server on your side (whether this is postfix, exim or whatever).

the SMTP-error you get (550) indicates that the gmail-mailservers do not recognize the recipient address as being one of theirs. so i would double check whether you really have "verifed my domain with google" (not clear what you mean by this).

finally, here's a suggested migration path that should minimize loss of email:

1. make sure all is working fine on your side (MX points to your smtp-server, and it accepts all the mails you want)
2. negotiate with googlemail that they accept your domain & email-addresses
3. test whether gmail actually accepts your email. personally i would manually do an SMTP connection to a gmail server, something like the simple telnet session at below
4. once gmail accepts emails for your domain, change the MX record to point to gmail. not before.

here is a telnet-session to verify an email address with google (it tries verifying joe@example.com and fails).

$ dig mx gmail.com
> [...]
> gmail.com.        705 IN  MX  10 alt1.gmail-smtp-in.l.google.com.
> [...]
$ telnet alt1.gmail-smtp-in.l.google.com 25
> [...]
> 220 mx.google.com ESMTP i8si336733lam.57 - gsmtp
HELO world
> 250 mx.google.com at your service
MAIL FROM: <>
> 250 2.1.0 OK i8si336733lam.57 - gsmtp
> RCPT TO: <joe@example.com>
> 550-5.1.1 The email account that you tried to reach does not exist. Please try
QUIT
$

(lines starting with $ are what you have to type in the shell, lines starting with > are responses (either from some command like dig or from the remote server) and the other lines are commands you have to type in the SMTP-dialog.)

Answer 2

Make sure you comment out:

smtpd_recipient_restrictions =
#        reject_unverified_sender

or else you'll get that 550-5.1.1 from Google