Email & port 25

NethServer Version: 7.2009
Module: Email

Hello again everyone.

A final issue, an one that appears to be common. I have set up my e-mail server and have created all of the appropriate DNS records. I have checked that my ISP allows connections to port 25 (it does). I am, however, still unable to receive mail.

Nethserver tells me that port 25 is unreachable.

I’ve run through all of the potential blocks to port 25 that I can think of: Nethserver network (I only have a green network); firewall; SMTP settings in relay; and router port fowarding.

When I check /var/log/maillog, I am told that

HELO command rejected: need fully-qualified hostname

I had HELO custom set to mail.[my domain], but that doesn’t seem to do the trick.

Any ideas?

Hi @Adam_P_Strombergsson

To check, I’d need your domainname… You can PM me the domainname.

I can check your connectivity with port 25 (I assume that’s not really the issue) but does your nethserver response on port 25 the way the pther side expects it, and you’re right that the smtp helo has to do with this…

This may help:


Custom Template addition for Postfix:

mkdir -p /etc/e-smith/templates-custom/etc/postfix/

cp /etc/e-smith/templates/etc/postfix/ /etc/e-smith/templates-custom/etc/postfix/

nano /etc/e-smith/templates-custom/etc/postfix/

Add in:
myhostname =

Save with CTRL-x y ENTER

expand-template /etc/postfix/

signal-event nethserver-mail-server-update

systemctl restart postfix
systemctl status postfix

Your DNS MX will normally point to a domain, not to a host, so set your smtp helo accordingly.
Also set your PTR (Reverse Lookup) accordingly, this is very important!

You can also this link to test your mail:

If you get 9/10 (except unsubscribe link…) you’ll have working mail. Pay attention to their replies, you have three tries / day!
β†’ a very valuable tool!

My 2 cents

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