Here are two useful Postfix commands that will help in everyday Postfix administration of forwarders.
Create a local forwarder
The point of a local forwarder is to ensure that all emails to a specific email address is delivered to another email address. In this instance, the first email address to which it’s directed does not have to exist. It’s a two step process:
cd /etc/postfix vim virtual
In the virtual file, the following will be needed to added, namely the TO: address, and the FROM: address. Example:
[email protected] [email protected], [email protected] [email protected] [email protected], [email protected]
Once the file has been modified, execute this command:
postmap virtual
You’re set! All email to the first column will now be sent to the comma delimited email address(es) in the second column.
Create a global domain forwarder
A global domain forwarder is useful when your mail server’s IP address is blocked and you want email to specific domains to be routed via another server. So email to a domain, e.g. @example.com, originating from Server A, must be sent via Server B.
The main prerequisite for this is to have a mail server that accepts email from the IP address of Server A. So on Server B, mail relay IP address settings must be added.
Then on Server A create a global domain forwarder:
vim /etc/postfix/transport
Add the following to the top of the file:
live.co.za smtp:[mailrelay.yourserver.com]:587 live.com smtp:[mailrelay.yourserver.com]:587 outlook.com smtp:[mailrelay.yourserver.com]:587 hotmail.com smtp:[mailrelay.yourserver.com]:587 office.com smtp:[mailrelay.yourserver.com]:587
References
- A brilliant Linux Engineer named Keith Williams
- https://kb.vander.host/knowledgebase/email/consolidated-list-of-pronounced-rbls-real-time-black-lists-and-experiences-in-de-listing/