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:

Wolfram Research (2015), ReturnReceiptFunction, Wolfram Language function,


Wolfram Research (2015), ReturnReceiptFunction, Wolfram Language function,


@misc{reference.wolfram_2021_returnreceiptfunction, author="Wolfram Research", title="{ReturnReceiptFunction}", year="2015", howpublished="\url{}", note=[Accessed: 17-October-2021 ]}


@online{reference.wolfram_2021_returnreceiptfunction, organization={Wolfram Research}, title={ReturnReceiptFunction}, year={2015}, url={}, note=[Accessed: 17-October-2021 ]}


Wolfram Language. 2015. "ReturnReceiptFunction." Wolfram Language & System Documentation Center. Wolfram Research.


Wolfram Language. (2015). ReturnReceiptFunction. Wolfram Language & System Documentation Center. Retrieved from