SmtpTransientErrorOccurredEventArgsReason Property
Gets the exception describing the error which prevented the message from being sent.

Namespace: MailBee.SmtpMail
Assembly: MailBee.NET (in MailBee.NET.dll) Version: 12.5.0 build 687 for .NET 4.5
Syntax
public MailBeeSmtpNegativeResponseException Reason { get; }

Property Value

Type: MailBeeSmtpNegativeResponseException
A reference to the exception.
Remarks
The error reason of TransientErrorOccurred events if always negative response from an SMTP server (it's pretty specific type of errors). Other errors like connection failures, network issues, etc won't case this event occur. So you can be sure that you have SMTP error code, human-readable description returned by the SMTP server, etc.
See Also