is an option for MailReceiverFunction that specifies what function to apply if a return receipt is requested for mail received by a MailReceiverFunction.


  • Typical settings include:
  • Truealways allow a return receipt
    Falsenever allow a return receipt
    funapply fun to determine whether to give a return receipt
  • With the setting ReturnReceiptFunction->fun, fun is applied to the same association as in MailReceiverFunction, but with an additional entry "Result" that gives the result from applying the function in MailReceiverFunction.
  • The function fun is only applied if a return receipt was requested for a particular piece of mail, as indicated by the value for "ReturnReceiptRequested" in the association supplied to MailReceiverFunction.
  • If the value obtained by applying fun is True, a return receipt is given; otherwise, it is not.


Basic Examples  (1)

Deploy a mail receiver that only allows return receipts for a certain domain:

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Introduced in 2015