Hello
I've just installed SP1 on existing Exchange 2013. After that I noticed, that e-mails from external addresses are not incoming. After investigation I found that problem is with self-signed certificates, which are used by Frontend default receive connector.
This is the error from log:
554 The security certificate was issued by a company you have not chosen to trust.
As workaround I can disable TLS on that connector or change fqdn for the connector to something else which prevents binding any certificate to the connector.
--- Jacek Kochan MCSE,MCSA,MCITP