Mail-tester not perfect result with a Nextcloud installation

1

Hi,

Mail tester result after a Nextcloud installation on my dedicated server:

Votre adresse IP 88.88.88.88 est associée au nom de domaine serveur.mydomain.com.

Néanmoins votre message semble être envoyé de cloud.mydomain.com.

Vous devriez modifier l’enregistrement du pointeur DNS (Type PTR) et le nom

d’hôte (host name) de votre serveur avec la même valeur

Voici les valeurs testées pour cette vérification:

IP: 88.88.88.88

HELO: cloud.mydomain.com

rDNS: serveur.mydomain.com

I have a HestiaCP on this server with several IP adress and few domain names on earch IP.

Regards.

2

Hi,

Exim sets the SMTP HELO identity by performing a reverse DNS lookup on the sending IP address and falling back to the server’s primary hostname if no PTR record is found.

Show the output of these commands from your server:

dig -x 88.88.88.88 +short
telnet 88.88.88.88 25

dig -x other.of.your.ips +short
telnet other.of.your.ips 25

Note: Use QUIT to logout from telnet session.

3 
mylocaluser@newtower:~$ dig -x 88.88.88.88 +short
serveur.mydomain.com.
mylocaluser@newtower:~$ telnet 88.88.88.88 25
Command ‘telnet’ not found, but can be installed with:
sudo apt install inetutils-telnet  # version 2:2.5-3ubuntu4.1, or
sudo apt install telnet-ssl        # version 0.17.41+really0.17-4
mylocaluser@newtower:~$ sudo apt install inetutils-telnet
Reading package lists… Done
Building dependency tree… Done
Reading state information… Done
The following packages were automatically installed and are no longer required:
libllvm19 libwayland-server0
Use ‘sudo apt autoremove’ to remove them.
The following NEW packages will be installed:
inetutils-telnet
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 100.0 kB of archives.
After this operation, 247 kB of additional disk space will be used.
Get:1 
 noble-updates/main amd64 inetutils-telnet amd64 2:2.5-3ubuntu4.1 [100.0 kB]
Fetched 100.0 kB in 0s (828 kB/s)
Selecting previously unselected package inetutils-telnet.
(Reading database … 40877 files and directories currently installed.)
Preparing to unpack …/inetutils-telnet_2%3a2.5-3ubuntu4.1_amd64.deb …
Unpacking inetutils-telnet (2:2.5-3ubuntu4.1) …
Setting up inetutils-telnet (2:2.5-3ubuntu4.1) …
update-alternatives: using /usr/bin/inetutils-telnet to provide /usr/bin/telnet (telnet) in auto mode
Processing triggers for man-db (2.12.0-4build2) …
mylocaluser@newtower:~$ telnet 88.88.88.88 25
Trying 88.88.88.88…
telnet: Unable to connect to remote host: Connection refused
4

But does your server have that public ip assigned (I suppose you are using the actual ip instead of 88.88.88.88)? Also, have you tried your other public IPs?

5

Sorry, I have lost time to read again:

$ telnet 88.88.88.88 25
Trying 88.88.88.88…
Connected to 88.88.88.88.
Escape character is ‘^]’.
220 cloud.mydomain.com
QUIT
221 cloud.mydomain.com closing connection
Connection closed by foreign host.

$ dig -x 88.88.88.88 +short
cloud.mydomain.com.

Other domain (on the same user) are ok.

6

I should only change the PTR on provider?

7

But the PTR for 88.88.88.88 is already the right one, don’t know why the mail tester said it is using another one.

I would like to know what’s the actual domain name and the actual IP.

8

I have found the solution, I think: I had should harmonize the reverse DNS to cloud.mydomain.com too.
I tell you the IP in a private message (lol).

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