Hi,Our Exchange environment looks like the following:1 x CAS Server1 x MBX/HUB Server1 x Reverse Proxy Server (ISA Server 2006)Our current Published external services are OWA and Secure IMAP.We currently have SAN SSL Cert setup for the CAS server for IMAP-S and OWA.What we would like to do is provide secure SMTP access for External IMAP users without a VPN.Can you please provide me with a detailed list of steps that need to take place before this can happen.Regards,Iss

Hi, You need to enable SMTP service on the Exchange certificate first. Enable-ExchangeCertificate -Thumbprint XXXXXXXXXXXXXXXXXXXXXXXXXX -Services "SMTP". On the received connector, enable Transport Layer Security and offer Basic authentication only after staring TLS. Then configure your client to use encrypted SMTP connection. Thanks, Elvis