Gets the reference to the data table used for mail merge of this message.
A reference to the data table used for mail merge of this message, or a null reference (Nothing in Visual Basic) if this mail message was not composed as a merge of database data with mail template.
For mail merge operations, e.MergeTable[e.MergeRowIndex] (in C# syntax, assuming e is an instance of SmtpMessageSentEventArgs class) returns DataRow used for mail merge of the message which could not be sent.
SmtpMessageNotSentEventArgs Class | MailBee.SmtpMail Namespace