Some environments must accept authenticated SMTP sessions from many remote locations that use dynamic IP addresses.
MailEssentials will typically block these sessions. Creating a separate SMTP virtual server for port 587 will allow these remote servers to bypass spam filtering for authenticated SMTP sessions. Note that in Exchange 2007/2010/2013, any connections that are authenticated through port 587 will bypass spam filtering by default.
- Create a new SMTP virtual server using port 587
- Configure the desired SMTP users to send through the new SMTP virtual server using port 587