Hello All,
I have my exchange 2019 server setup and working fine for passing mail. OWA and the wildcard cert I have works fine for OWA, mail clients, etc. No problems with normal mail flow, or utilizing the wildcard cert I purchased from Sectigo RSA Domain Validation Secure Server .
I do have an issue when attempting to telnet into Exchange using openssl in order to run starttls. I am able to get connected via openssl and I am passed a certificate from the exchange server, BUT it is not the certificate I am expecting. Instead of getting the wildcard certificate from Sectigo RSA Domain Validation Secure Server , I am getting a self signed certifcate. Which is why I believe my Ehlo after starttls fals with '501 5.5.4 Invalid domain name'.
Looking at EAC I have four certificates total
Name: Microsoft Exchange, self signed certificate, assigned services: SMTP
Name: Microsoft Exchange Server Auth Certificate, self-signed certificate, assigned to services SMTP
Name: Wild, Sectigo RSA Domain Validation Secure Server, assigned services IMAP, POP, IIS, SMTP
Name: WMSVC-SHA2, self-signed certificate, assigned to services SMTP.
Can I remove any of the self-signed certificates?
Is there a way to specify when using openssl to specify which certificate it should use?
my understanding is IIS needs the WMSVC-SHA2 cert....
To keep it short, you need them certificates, otherwise exchange OWA/ECP, etc.. it won't work.
That's because you do not need wildcard for exchange, you need to expedite the SAN certificate once more and redeploy it.
You need two domains.
Mail.domain.com
autodiscover.domain.com
If you use wildcard whenever you type your domain you're not telling specifically to exchange what domain name to look for.