[TUTORIAL] Get Postfix to Send Notifications (Email) Externally

[Seed]

I'm not sure I did this in the proxmox way but I couldn't get email to relay to me and some posts were dated or didn't work for me, so I did the following:

Gmail for example:

Change /etc/postfix/main.cf to include/change these lines:

relayhost = [smtp.gmail.com]:587
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

#mydestination = $myhostname, localhost.$mydomain, localhost

Be sure there are no dupes as the main.cf may have smtp_sasl_security_options = {} , and relayhost = {}. Just delete or comment those lines.

Create an /etc/postfix/sasl_passwd file with:

[smtp.gmail.com]:587    testmehere@gmail.com:PASSWD

run

chmod 600 /etc/postfix/sasl_passwd
postmap /etc/postfix/sasl_passwd

install for passwd support:

apt-get install libsasl2-modules

Restart service:

systemctl restart postfix.service

Test:

echo "Test mail from postfix" | mail -s "Test Postfix" test@test.com

Test from PVE:

echo "test" | /usr/bin/pvemailforward

Logs:​

/var/log/mail.warn

is helpful as well as

/var/log/mail.info

Customize From:
This is nice so it's not from "root"​

Create smtp_header_checks file, this changes all outgoing mail:

/^From:.*/ REPLACE From: HOSTNAME-alert <HOSTNAME-alert@something.com>

Add to main.cf:

smtp_header_checks = pcre:/etc/postfix/smtp_header_checks

Don't forget to run postmap on the header file

#note. For pcre support you'll need to install apt install postfix-pcre and restart postfix service

 

[Stoiko Ivanov]

Thanks for sharing this - the config looks quite right!

(You could consider using the 'TUTORIAL' prefix for your thread - that makes the thread stand out visibly)

 

[ChESch]

I have tried this and struggle with the problem that my proxmox runs behind a dynamic IP which is on many blacklists. So even though everything is configured right, I get rejected from the mailserver. Is there a way to configure postfix as MUA and not as MTA? So that it would work with dynamic blocked IPs on any mail-server?

 

[ChESch]

I have tried this and struggle with the problem that my proxmox runs behind a dynamic IP which is on many blacklists. So even though everything is configured right, I get rejected from the mailserver. Is there a way to configure postfix as MUA and not as MTA? So that it would work with dynamic blocked IPs on any mail-server?

It seems like the described problem does not occur when SSL/TLS is used, so I don't have this problem anymore.
Thanks for this guide!

 

[greg91]

Hello, just wanted to say thank you for this tutorial, after days of searching I finally got it working with this!

 

[Seed]

Happy it worked for ya

 

[Tommmii]

The custom From: should be

 # for outgoing changes only "smtp".
smtp_header_checks = pcre:/etc/postfix/smtp_header_checks

 

[Seed]

The custom From: should be

 # for outgoing changes only "smtp".
smtp_header_checks = pcre:/etc/postfix/smtp_header_checks

How is this any different than the guide?

 

[Tommmii]

This does not work and throws errors in syslog :

smtp_header_checks = pcre:/etc/postfix/smtp_header_checks . #for outgoing changes only "smtp".

This works without errors :

# for outgoing changes only "smtp".
smtp_header_checks = pcre:/etc/postfix/smtp_header_checks

 

[guletz]

The problem is the dot: "smtp_header_checks . #"
Correct will be:

smtp_header_checks = pcre:/etc/postfix/smtp_header_checks # for outgoing changes only "smtp".

Thx. for the tutorial!

Good luck /Bafta

 

[Seed]

The problem is the dot: "smtp_header_checks . #"
Correct will be:

smtp_header_checks = pcre:/etc/postfix/smtp_header_checks # for outgoing changes only "smtp".

Thx. for the tutorial!

Good luck /Bafta

Ahh thank you for clarifying that. Will change.

 

[guletz]

you for clarifying that. Will change.

welcome; )

 

[Hyacin]

Awesome guide, thanks! I kept seeing log messages from Postfix complaining about not being able to send mail or whatever, so I finally got around to looking up up how to fix it! q: Who is it going to send email *to*? Will it be the email address I provided during installation? Because I've never seen a field for an email address anywhere in the configuration that I can recall.

 

[Tommmii]

Who is it going to send email *to*? Will it be the email address I provided during installation?

Yes, also see : https://forum.proxmox.com/threads/how-to-chage-notification-email-address.30241/

 

[Stoiko Ivanov]

Will it be the email address I provided during installation? Because I've never seen a field for an email address anywhere in the configuration that I can recall.

yes initially it's the email address you set during installation - you can customize this in an installed PVE system - by setting the email of the user root@pam (GUI->Datacenter->Users)

I hope this helps!

 

[bferrell]

Great tutorial, and I have tested on my primary node (the one I use to monitor my cluster), but should this be done on every node in the cluster?

 

[wegiii]

The problem is the dot: "smtp_header_checks . #"
Correct will be:

smtp_header_checks = pcre:/etc/postfix/smtp_header_checks # for outgoing changes only "smtp".

Thx. for the tutorial!

Good luck /Bafta

This was still throwing fatal errors for me. Did what @Tommmii suggested and it works correctly. Thanks!

Great tutorial, and I have tested on my primary node (the one I use to monitor my cluster), but should this be done on every node in the cluster?

I have only done this on my main node as well, but will implement across all nodes as I imagine this has to be done on each one.

@Seed - Thank you for this tut!

 

[Seed]

This was still throwing fatal errors for me. Did what @Tommmii suggested and it works correctly. Thanks!

I'm not sure why this would cause an error. The original guide was updated to not include that typo a long time ago.

 

[wegiii]

I'm not sure why this would cause an error. The original guide was updated to not include that typo a long time ago.

I'm not sure. I moved the comment above the config line, rather than after, restarted postfix, emails started going out. Thanks again.

 

[SynCron]

Thank you for the instructions. I followed step by step but my mail.info shows

connect to smtp.gmail.com[2607:f8b0:4023:c03::6c]:587: Network is unreachable

And mail.warn shows

warning: symlink leaves directory: /etc/postfix/./makedefs.out

Attached is my main.cf - any suggestions?