Can't receive mails from external accounts

Hello everybody !!

I would like get some help on a mail issue. Any help would be appreciated. :slight_smile:

I just installed a fresh new CyberPanel environment on a VPS running centOS7.
My CyberPanel version is 2.1.2 and after this upgrade i can’t receive mails from external accounts anymore. I can send and receive mails between accounts in my domains, but mails sent from external domains/accounts (gmail or hotmail for example) are rejected and sender receive a “service unavailable” message.

Looking for something wrong into system log, i found this:
sendmail[22173]: STARTTLS=client, relay=[], version=TLSv1/SSLv3, verify=FAIL, cipher=ECDHE-RSA-AES256-GCM-SHA384, bits=256/256
My guess is that message refers some SSL issue…

After spent many hours looking for some light over this on web, i found this article:
so i decided follow it, and bellow are some considerations:

1 - Postfix are running fine in my system

2 - I enabled system debug as suggested here:

And analising messages on erro-logs.txt i could observe that the system wasn’t able to create a self-signed certificate for mail domains… bellow image about it generated when i tried to create a self signed certificate for a mailserver.

Well, could you please help me on this issue?

Generate letsencrypt ssl instead of self signed ssl.
Under websites menu of cyberpanel, click on List domains and then select the relevant mail subdomain and click on issue ssl.

Thanks a lot die2mrw007 for your reply !!

Using issue ssl on domains list i could generate a valid ssl for mail domains with no more error messages… it’s ok. However, i still isn’t able to see arriving mails on mail boxes, the problem persist.

When i send a message from hotmail, for example, to my domain boxes (any), i still see the follow message into error log:

sendmail[623982]: STARTTLS=client, relay=[], version=TLSv1/SSLv3, verify=FAIL, cipher=ECDHE-ECDSA-AES256-GCM-SHA384, bits=256/256

Any idea about ??

After doing the changes have you restarted postfix and dovecot?
Try restarting the whole server by sudo reboot command and see if that solves.