 | 1 | initial version |
Most likely the certificate is invalid.
In frame 2651 the Client Hello contains the SNI "autodiscover.companyB.com". In frame 2710 the server sends its certificate. This is followed by a TCP FIN -- that should have been a TLS alert by the way.
So the client concludes something is wrong. For example the certificate does not match the SNI name or the certificate chain is invalid.
Without a proper TLS alert, the only way to know the reason is to dig in the application (debug?) logging.
You can also check the certificate manually with the opensll command:
openssl s_client -connect autodiscover.companyB.com:443 -servername autodiscover.companyB.com