Issue Problem with sending emails (not matching your DNS configuration)

[igork1]

I have a problem with sending emails from my VPS server to many servers (Gmail accepts emails). I will be grateful for any advice.

Apr 9 06:41:09 vps-xxxxxxx postfix/smtp[20867]: 15359222C6: to=<[email protected]>, relay=mx.tb.ukmail.iss.as9143.net[212.54.xx.xx]:25, delay=239714, delays=239714/0.03/0.07/0, dsn=4.0.0, status=deferred (host mx.tb.ukmail.iss.as9143.net[212.54.xx.xx] refused to talk to me: 421 EHLO MXIN201 Your HELO/EHLO laughing-cerf.54-36-xxx-xxx.plesk.page is not matching your DNS configuration vps-xxxxxxx.vps.ovh.net

It's a new Debian 10.9 installation with Plesk Obsidian 18.0.34 Update 2. All emails settings are set by default.

Plesk manages DNS records for my website. DKIM and SPF are enabled.

Full hostname in Plesk settings: vps-xxxxxxx.vps.ovh.net

 

[Kaspar]

The warning Your HELO/EHLO laughing-cerf.54-36-xxx-xxx.plesk.page is not matching your DNS configuration vps-xxxxxxx.vps.ovh.net usually means that the reverse DNS (rDNS) is not configured correctly. Make sure the IP address of your VPS points to vps-xxxxxxx.vps.ovh.net. Contact OVH support if you're not able to configure this yourself.

 

[igork1]

Thanks for your reply!
Honestly, I didn't configure reverse DNS. I'll learn how to do it with OVH. Regrettably OVH almost never respond on queries.

 

[igork1]

I configured reverse DNS for my server in OVH control panel. Now my IP is linked with my domain name in reverse DNS settings.

However I still have the same problem with sending emails:

421 EHLO MXIN201 Your HELO/EHLO laughing-cerf.54-36-xxx-xxx.plesk.page is not matching your DNS configuration MyDomain.com

In Plesk > Full hostname is set to vps-xxxxxxx.vps.ovh.net

I use Let's Encrypt.

“SSL/TLS certificate for mail“ = (Not Set)
“Send from domain IP addresses” is ON

Please give any advice,

 

[igork1]

Up

 

[igork1]

 

[Bitpalast]

The advice or @Rasp was not to change the hostname in your reverse DNS setting, but to simply set reverse DNS. Now, as you have changed the hostname there, you also need to rename your host to match the rDNS name. You also seem to have a different host name in Plesk than what is configured in /etc/hosts on your server. All this must match to fix the error.

 

[igork1]

Peter,

Thanks for your reply! I have the following settings now:

(Plesk) Full hostname: vps-xxxxxxx.vps.ovh.net

OVH control panel:
IP: 51.195.xxx.xxx
Service: vps-xxxxxxx.vps.ovh.net
Reverse DNS: mydomain.com.

/etc/hosts
127.0.1.1 vps-xxxxxxx.vps.ovh.net vps-xxxxxxx
127.0.0.1 localhost

421 EHLO MXIN201 Your HELO/EHLO laughing-cerf.54-36-xxx-xxx.plesk.page is not matching your DNS configuration MyDomain.com

 

[Bitpalast]

And in Plesk you are using laughing-cerf.54-36-xxx-xxx.plesk.page. You need to update that hostname in Plesk, too.

Changing Your Server’s Host Name

You specify your server’s host name during your very first login to Plesk. If you want to change the host name later,...

docs.plesk.com

 

[igork1]

Earlier Full hostname in Plesk was set to laughing-cerf.54-36-xxx-xxx.plesk.page.
And I had the same problem. Then I changed it to vps-xxxxxxx.vps.ovh.net and rebooted VPS (it didn't help).

I see in maillog a mention of laughing-cerf.54-36-xxx-xxx.plesk.page. but where this parameter is set in Plesk?

Current Full hostname is vps-xxxxxxx.vps.ovh.net

Should I change Full hostname to mydomain.com in Tools & Settings > Server Settings ?

 

[Kaspar]

It is best to use a sub-domain from a domain you own your self for the hostname of your server/vps. Because that gives you full control to manage the DNS records.

So set the Full hostname in Plesk to somehting.mydomain.com (a sub-domain, not just mydomain.com). Then create a DNS record to point to you new hostname. And lastly set the reverse DNS to your match your new hostname. That's it. When done right, it should solve your issue.

 

[igork1]

Rasp,

Thanks for your idea! I'll try it on Monday.

Then create a DNS record to point to you new hostname.

Plesk automatically manages my DNS records, when I create a new domain or sub-domain in Plesk. Should I simply add a new sub-domain in Plesk?

 

[Kaspar]

Plesk automatically manages my DNS records, when I create a new domain or sub-domain in Plesk. Should I simply add a new sub-domain in Plesk?

No, do not create/add the sub-domain you want to use as your server/vps hostname separately to Plesk. Instead go to mydomain.com in Plesk and go to the DNS settings for this domain and create a DNS record for the sub-domain you want to use as your hostname. For example if you want to use controlpanel.mydomain.com as the hostname for your server/vps add an A record for controlpanel and point it to the IP address of your server/VPS. Like so:


(Don't forget to click the update button afterwards to apply the DNS changes).

 

[igork1]

Hi,

Many thanks for your advices! I'll try today.

 

[igork1]

It seems that suggested change has solved my problem with "421 EHLO MXIN201 Your HELO/EHLO laughing-cerf.54-36-xxx-xxx.plesk.page is not matching your DNS configuration vps-xxxxxxx.vps.ovh.net".

However I found a new problem with sending to many Gmail addresses which appeared after a recent change:

Apr 27 07:38:35 revers postfix/smtp[4927]: 1AD5322266: host gmail-smtp-in.l.google.com[142.250.xxx.xx] said: 421-4.7.28 [51.195.xxx.xxx 15] Our system has detected an unusual rate of 421-4.7.28 unsolicited mail originating from your IP address. To protect our 421-4.7.28 users from spam, mail sent from your IP address has been temporarily 421-4.7.28 rate limited. Please visit 421-4.7.28 Prevent mail to Gmail users from being blocked or sent to spam - Gmail Help to 421 4.7.28 review our Bulk Email Senders Guidelines. j4si1969757edk.420 - gsmtp (in reply to end of DATA command)

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