I test (also the left certificate lifetime with check_mk https://mathias-kettner.com/features.htm).

It's not that easy. I guess openssl should be able to test and it is installed on Application Server.

If you search for SSL test in Google you find a lot of pages that can check certificates but only a very few of those are able to handle different ports than 443. I don't have one link saved so - sorry - you have to test them yourself.

Need some help with IP Office? https://www.fwilke.com/home
IP Office SIP trunk configuration: https://www.fwilke.com/en/ip-office-sip-trunk-en/
CLI based cale blocking: https://blog.fwilke.com/ip-office-block-calls-from...
SCN fallback over PSTN: https://blog.fwilke.com/ip-office-scn-fallback/

Try this handy utility, there is a tool in it that will check the install of a certificate and it's chain, just enter the sever address and port

https://www.digicert.com/util/

“Some humans would do anything to see if it was possible to do it.
If you put a large switch in some cave somewhere, with a sign on it saying 'End-of-the-World Switch. PLEASE DO NOT TOUCH'.
The paint wouldn't even have time to dry.”

Terry Pratchet

Thank you. The certificates seem to be ok. I put the FQDN in a tool from sslshopper.com