Custom helo/smtpd greeting question


NethServer Version: 7.3.1611 (Final)
Module: Email

A little background is I’m moving from a Xmail/Dovecot Ubuntu 16.04 based system as Xmail appears very dead. I’m in the process of bringing up the system. I know I need to transfer the certs still and while Thunderbird >45 is fine my users with Outlook 2016 refuse to connect which I think is because Microsoft is now rejecting part of TLS but that us another issue for another post.

I use for my server check and it seems fine but for reverse dns. My ISP has the PTR with the main domain of My host name is and was on the other machine. In XMail I had to change HELO_DOMAIN to and set ROOT_DOMAIN to my ISP domain or it wouldn’t work. My certs are domain tied to

Okay so I read the manual and see a command for postfix custom helo and use it but when I test with telnet the helo response is still the host name of It was pointed out to me I forgot the “-” at the end of the su command. I also found the postfix file and checked that the change took place. It did. I restarted the server form Nethserver service screen but so far it is still reporting the host name 250

Getting the ISP to change the PTR is a drwan out affair like they think I want a few pints of their blood or something so if I can get the reverse DNS to pass then I believe gmail, ymail, hormail etc should start being received again. Again, for another post about the reverse DNS but don’t see why that is any issue as all was good before; just the anti relay issues with the improper helo repsonse is what I’m after at present please.

I appreciate any tips even if they are along the lines of I need to change PTR, hostname, DNS or whatever.

The custom HELO/EHLO procedure is documented here

It acts when a message is sent by the smtp client. It does not affect the smtp server response. IIRC Postfix has a different parameter for it. The default value, as you see, is the host FQDN.


Thanks, that is the doc I worked from. The nature of this topic is about learning best practices for Nethserver I am guessing as I think I am too new to the system to know if I am asking the right questions. I am not new to admin work just to how I need to configure things in Neth properly. What I expected to work per documents did not so I am missing something in my understanding. Thank you for your patience.

I can see has a new value from running the command sequence but it is not live per telnet test and responses 220 and 250 were not showing the config property change. I restarted postfix several times from the web GUI and from a shell to no avail. Being new to a CentOS/Nethserver system I don’t want to hand configure things though I did as a test explained below.

Other guides for postfix talked about setting $mydomain so I did:

myhostname =
mydomain =
myorigin = $mydomain

At the top of /etc/postfix/ under the warning to not edit the file with manual changes being lost after it is regenerated. After a postfix service restart, a telnet test showed the change, which is great. For Windows users and outlook that do not have a FQDN, I also commented out the smtpd_helo_restrictions section.

I have read Neth documents concerning e-smith flat file database configuration and was in search of how it affects the email server configuration when I saw the previous response to this topic.

So…how do I go about making the changes properly to make this configuration permanent ? I’m sure the lesson will apply to the rest of how the Neth configuration works so should be helpful in a big way :slight_smile:

Thanks !

Do not change it! It’s used almost everywhere and it’s hard to predict what actually changes!

I’d start by adding/changing smtpd_banner in

The run

systemctl restart postfix

If it works as expected we can move to the next step: how to make a custom-template, as documented here

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I replaced the $mydomain parameter in with $smtpd_banner. The smtpd 220 indicates which is great and 250 which is, I don’t know but the gmail issues are fine. So, how to make this a proper edit ?

I am reading the custom template doc. I will see if I can make one adding $smtpd_banner and removing $smtpd_helo_restrictions (unless anyone know of a better way to handle Windows Outlook clients not having a FQDN)

Thanks !