Linux server forwarding mails
Posted 9/25/2014
Setting up a linux server to forward all incoming mails
Typical thing when having a new site up: you want to get whatever@yourdomain.com to end up in you normal inbox, say Gmail. Usually, websites selling domains offer this feature as a service. But if you find yourself in the situation to go all manual, here are the steps.
Note: This guide is written for Debian-based distros. If you are logged in as root, you do not need to use “sudo” in front of each command.
Preparations
It’s recommended to have a user account to receive the mail other than root. So either choose a user you have created already or create a new one:
sudo adduser [username]
Does your provider require you to use an SMTP relay? (check the documentation, or ask). You need to know this to continue.
Install postfix
Postfix is a software package, a MTA, it handles incoming mail and forwarding.
sudo apt-get install postfix
And answer all configuration questions as below, replace […] with your domain:
Server configuration type: If you use an SMTP relay, choose “Internet with smarthost”, otherwise “Internet”.
| Question | Configuration |
|---|---|
System mail name | [yourdomain.com] (no subdomains) |
SMTP relay host | [smtp.yourprivider.com] (only showing if you chose “Internet with |
Root and postmaster mail recipient | The name of the user created/chosen before (not root) |
Other destinations to accept mail for | keep the suggested defaults and add in front |
Force synchronous updates on mail queue | no |
Local networks | keep suggested |
Use procmail for local delivery? | yes |
Mailbox size limit | 0 |
Local address extension character | + |
Internet protocols to use | all |
Manual configuration
Edit /etc/postfix/main.cf (e.g. with sudo nano ...) add following two lines to the end:
virtual_alias_domains = [yourdomain.com]
virtual_alias_maps = hash:/etc/postfix/virtual
Create/edit /etc/postfix/virtual and add:
@[yourdomain.com] [your.email.address@somewhere.com]
Finally, after editing this file run:
sudo postmap /etc/postfix/virtual
so that postmap actually applies your changes.
Notes
If you forward to Gmail, do not use the same address to send test mails that the mails will be forwarded to—Gmail will silently ignore/delete mail where the sender and recipient are the same and you will think the forwarding does not work. How do I know? Don’t ask. 😅