Issue Domain cannot recognize Plesk server SSL certificate

[EricRB]

I don't know when this problem first started. I just noticed that on a recently added subscription, the customer had selected his own domain LetsEncrypt cert for Mail. But I have set the Server to use the Plesk Server SSL cert for mail, server wide. I know before I could see both the server cert and the domain cert in the drop down box in the domain mail settings, so you could choose either one, but now none of the domains will recognize the Server Cert for mail, even though it is set as the server-wide mail cert. The only thing I did pertaining to mail that could remotely have affected this (longshot maybe) is I had uninstalled SSL-It extension in favour of just having LetsEncrypt there, then when I found this problem, today,(don't know how long the problem is there for), I thought maybe uninstalling SSL-It maybe screwed things up, so I re-installed the SSL-It extension. But that did nothing to fix the problem, and I fail to see why it would or why it would have anything to do with it. I was simply trying anything I could think of. Has anyone seen this problem. CentOS 8 Obsidian 18.0.34 Update #2