Return Value

Type: EmailAddressCollection
In "send to relay SMTP server" mode, returns the list of the recipients rejected by the SMTP server; in direct send mode (performing DNS MX lookup and sending to SMTP MX servers), returns the list of all recipients who did not receive the message.

If refused recipients were not allowed in send to relay SMTP server mode (AllowRefusedRecipients is false), the component will throw an exception after the refused recipient was encountered. It means the recipients which reside in the recipients list beyond the position of the refused recipient will not appear in GetAcceptedRecipients and GetRefusedRecipients collections.