The name or address of a mail server (internet post office server).
This property specifies the IP address (IP number in dotted internet format) or the Domain Name of the mail server. It is set before a connection is attempted and cannot be changed once a connection is in progress.
If this; property is set to a Domain Name, a DNS request is initiated and upon successful termination of the request, this property is set to the corresponding address. If the search is not successful the class fails with an error.
If the class is configured to use a SOCKS firewall, the value assigned to this property may be preceded with an "*". If this is the case, the host name is passed to the firewall unresolved and the firewall performs the DNS resolution.