Return Value

Type: Int32
If the server restricts the maximum message size and supports ESMTP SIZE extension, the return value is the maximum length of the message (in bytes) which is allowed by the SMTP server in order to accept the message from the client; otherwise, the return value is 0.

This property value is obtained from the server capabilities list which is received from the server during initial greeting (Hello method). Thus, the application must be already connected to the server and Hello method already called in order to use GetMaxMessageSize method. Even then, this method will still return zero if ESMTP SIZE extension is not supported by the server.