Log Name:      Application
Source:        MSExchangeTransport
Date:          23/06/2022 09:31:47
Event ID:      12016
Task Category: TransportService
Level:         Error
Keywords:      Classic
User:          N/A
Computer:      Exch01.domain.local
Description:
There is no valid SMTP Transport Layer Security (TLS) certificate for the FQDN of mail.domain.co.uk. The existing certificate for that FQDN has expired. The continued use of that FQDN will cause mail flow problems. A new certificate that contains the FQDN of mail.domain.co.uk should be installed on this server as soon as possible. You can create a new certificate by using the New-ExchangeCertificate task.
Event Xml:

 
   
    12016
    2
    12
    0x80000000000000
   
    17826307
    Application
    Exch01.domain.local
   
 
 
    mail.domain.co.uk
    F7646815BCE6A50EAAC3666D3958C87C11053C89