External lookup before internal lookup?

[billyrob]

Hi All,

Problem:

MX records of a domain point to an external Exchange Server. A records point to a different web server where Postfix is installed. Application on this server needs to send mail to the external Exchange Server but the mail fails as the mail is not found on the local Postfix server

Error Report:

Oct 5 18:52:46
postfix/pipe[28433]
5E2FF69C0F: to=<admin@somesite.co.uk>, relay=maildrop, delay=0, status=bounced (user unknown. Command output: Invalid user specified. )

I am a real newbie with Postfix but this is driving me mad! Can Postfix be forced to lookup an MX record before trying to send to a local account?

Thanks in advance.

 

[ElCantoDelLoco]

I think you should try to set in /etc/postfix/main.cf :

myhostname = your_machine.your_domain
mydomain = your_domain
...
relayhost = [@IP Exchange]


In your file /etc/postfix/transport put:

your_domain smtp:[@IP Exchange]

Then do :

postmap /etc/postfix/transport
/etc/init.d/postfix reload


Hope it will help you.