Why cert error for this ms outlook?

The "full" name used for the access is not in the certificate.

Note that the name Autodiscover is only used for configuration, Another name has been configured in Exchange to access the data.

Have you configured a CNAME for Autodiscover in all domains (abc.com, def,com, ghi.com and Proseware.com) defined in the local DNS ?

If I had a quid for every time :)...........
The name of the security certificate is invalid or does not match the name of the site



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What you'll get, from the above command, is output like this...

# echo QUIT | openssl s_client -connect davidfavor.com:443 2>&1 | openssl x509 -noout -text | egrep -e DNS: -e "Not After"
            Not After : Dec 18 20:06:44 2021 GMT
                DNS:*.davidfavor.com, DNS:davidfavor.com

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So you'll see the expiration date, along with each property covered... which in this specific case is a wildcard cert covering all hosts for this domain, along with the bare domain.

Hi all,

Please give me some time to go through your suggested steps

Hi Pete Long,

Thanks for sharing the various URL settings for internal and external. However, think the server side is working fine. The problem should be only on this user desktop.

There's still a server side problem...

# This is correct, although best avoid CloudFlare at all costs, if stable tech is your goal...
net15 # echo QUIT | openssl s_client -connect def.com:443 2>&1 | openssl x509 -noout -text | egrep -e DNS: -e "Not After"
            Not After : Nov 15 23:59:59 2022 GMT
                DNS:sni.cloudflaressl.com, DNS:*.def.com, DNS:def.com

# This is incorrect, so no lookup for the autodiscover host will ever work...
net15 # echo QUIT | openssl s_client -connect autodiscover.def.com:443 2>&1 | openssl x509 -noout -text | egrep -e DNS: -e "Not After"
unable to load certificate
140332014576960:error:0909006C:PEM routines:get_name:no start line:../crypto/pem/pem_lib.c:745:Expecting: TRUSTED CERTIFICATE

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So what appears to be happening.

1) Your wildcard cert covering *.def.com (all hosts) is correct.

2) Your HTTPS config for autodiscover.def.com is incorrect.

Fix: Is to add an HTTPS stanza to cover the autodiscover host.