Exchange Server 2013 provides a high level of security for
client-server and server-server communications by using
certificates to secure protocols such as HTTP, SMTP, POP and
IMAP. Because of the “secure by default” requirements, when an
Exchange 2013 server is installed it is configured with self-
signed certificates that are enabled for those protocols. Here
is an example of the self-signed certificates installed on a new
Exchange 2013 server. [PS] C:\>Get-ExchangeCertificate | Select
Subject,IsSelfSigned,Services | ft -auto Subject IsSelfSigned
Services ------- ------------ -------- CN=Microsoft Exchange
Server Auth Certificate True SMTP CN=E15MB1 True IMAP, POP, IIS,
SMTP CN=WMSvc-E15MB1 True None Although this means that services
such as Outlook Web App, Outlook Anywhere, and Activesync are
secure right from the moment the Exchange server is installed,
the use of self-signed certificates is only intended to be
temporary while the administrator acquired the correct SSL
certificates for the server. SAN/UC