# Setting up email sending

1. create a backup of your postfix config: `cp /etc/postfix/main.cf /etc/postfix/main_bak.cf`
2. open `/etc/postfix/main.cf`
3. add the following rows (make sure none of the rows are duplicated) ```
    #mydestination = $myhostname, server.local, localhost.local, , localhost # you can comment this out
    relayhost = [smtp.mail.com]:465 # replace this domain with your mail server
    smtp_use_tls = yes
    smtp_sasl_auth_enable = yes
    smtp_sasl_security_options = noanonymous
    smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
    smtp_tls_CAfile = /etc/ssl/certs/ca-certificates.crt
    smtp_tls_wrappermode = yes
    smtp_tls_security_level = encrypt
    
    # If your mail provider doesn't support ipv6, add/change this line
    inet_protocols = ipv4
    ```
4. create this file: `/etc/postfix/sasl_passwd` with the following content: ```
    [smtp.mail.com]:465    test@mail.com:PASSWD
    ```
5. make it only readable by your user: `chmod 600 /etc/postfix/sasl_passwd`
6. then: `postmap /etc/postfix/sasl_passwd`
7. install for passwd support: `apt install libsasl2-modules`
8. restart postfix: `systemctl restart postfix.service`
9. you can test it multiple ways: ```
    echo "Test mail from postfix" | mail -s "Test Postfix" test@test.com
    OR
    echo "test" | /usr/bin/pvemailforward
    ```
10. logs can be found here: 
    - `/var/log/mail.warn`
    - `/var/log/mail.info`

##### Common Issue:

If you can't send emails, because the domain in the FROM address is pointing to your server and the configured mail server rejects the mails with the following error:

```
Sender address rejected: Domain not found (in reply to RCPT TO command))
```

Then go to `Datacenter -> Options -> Email from address` and change it from `root@$hostname` to something that your mail server will accept.

Sources:

- [https://forum.proxmox.com/threads/get-postfix-to-send-notifications-email-externally.59940/](https://forum.proxmox.com/threads/get-postfix-to-send-notifications-email-externally.59940/)
- [https://www.digimoot.com/proxmox-setup-email-service/](https://www.digimoot.com/proxmox-setup-email-service/)