Postifx disable local delivery

Question

is there any form to prevent local delivery on a postfix server?

Ideally, I want to avoid local delivery to some domains, because this postfix server is a google apps backup one.

Thanks in advance, Simon.

Answer 1

In order for postfix to know not to deliver mail for a domain locally, you will need to make changes to a few (if relevant to your setup) config variables in main.cf - from the official postfix docs, you'd need to make sure you remove all domains you don't want to be treated as local from the following variables:

• mydestination: this usually contains the list of domains delivered locally
• local_recipient_maps: lookup table containing local recipient addresses
• local_transport: default transport for local mail - change if inet_interfaces or proxy_interfaces match the destination of a mail
• virtual_mailbox_domains: same as mydestination, if you're making use of it

Beyond that, I recommend you:

• use postconf at the command line to get quick access to the current values in postfix configuration variables (man postconf for more detail)
• visit the postconf/main.cf info page on the official postfix site for all the details

Yes, postfix can be complicated - but that's the beauty of its configurable nature.

Hope this helps!

Answer 2

I am not sure if this is the ideal solution, but I have a box with a single domain and this worked for me. I'm using Google Apps for email, and we have postfix installed to send out transactional emails, which end up going through sendgrid to be delivered to our site's users.

I found that postfix was filling up /Maildir with thousands of messages and eating up the disk space on my system.

I changed the following in etc/postfix/main.cnf:

mydestination = ip-{IP-ADDRESS-HERE}.ec2.internal, localhost.ec2.internal, , localhost

To:

mydestination = localhost

Where {IP-ADDRESS-HERE} is your IP, e.g. 10-100-10-10

After rebooting postfix, I tested and messages are still being successfully sent to sendgrid and out via postfix, but now my maildir is no longer being filled with unnecessary messages.