Question Even with certificate, webmail is not secure.

[CobraArbok]

Server operating system version

Ubuntu 22.04.4 LTS

Plesk version and microupdate number

Plesk Obsidian Version 18.0.58 Update #2

I updated a domain's expired certificate a few weeks ago with the one provided by the ISP.
The site is considered secure, while the webmail is not.
In Plesk, on the SSL page also for webmail there is a green icon and "Secured : Webmail is secured by a separate certificate".
I also tried from another browser in private mode, so it's not a cache problem. What could it be?

 

[tkalfaoglu]

normal SSL certificates only protect www.blah.com and blah.com, not webmail.blah.com. If you have a wildcard, then anything.blah.com would be protected..

 

[AYamshanov]

Since we do not know many details about your domain/certificate; makes sense to check alternative names listed in the certificate. When you open "webmail.example.org", usually in browsers it is possible to open certificate and see its fields. Here is a screenshot of a wildcard certificate, it contains two DNS Name, one for domain, another one with wildcard. Does your certificate contain "webmail" or wildcard inside? If not, it could be the reason.

 

[CobraArbok]

@tkalfaoglu
@AYamshanov
I solved it, thanks.
The old SSL certificate expired on March 3 and renewed on the 5th. It was subsequently installed again in Plesk for all subdomains.
What I didn't do (and I don't remember reading it in the documentation) is that I then have to go into "Domains / Mail Settings" and select the new certificate in the fields SSL/TLS certificate for webmail and SSL/TLS certificate for mail.

Other times in the past I have renewed the Lets's Encrypt SSL certificates as well as migrated the SSL server without having any problems; I also managed to configure Plesk and domain to get maximum spam test scores.
After migrating to a new VPS and updating the SSL certificate at the same time, the problems started, including the rejection of my emails from all GMail mailboxes (there is a second post of mine).
I was hoping that the two things were connected, but I see that even having solved the problem of the SSL certificate for webmail, I still cannot send emails to GMail mailboxes.