Spam filtering imports users' address books to compile a whitelist of allowed senders. Whitelists and blacklists of senders can be created. DKIM's non-repudiation feature prevents senders (such as spammers) from credibly denying having sent an email. Acknowledgments allow senders to determine when to retransmit lost packets. "AntiSpam" can sync its own list of allowed senders with POP3 address books. Setting up DMARC may have a positive impact on deliverability for legitimate senders. Finally, the feedback process addresses the reciprocal influence of the senders and the receivers. This messaging type is built on the concept of message queues, senders, and receivers. Notice that both devices involved in a transfer are considered senders and receivers. This form of communication allows senders and receivers to build long term trust and cooperation. The message explains that the senders are looking for their child. Senders or signatories of such letters become identified with the particular issue. Yogi helps Jaya get rid of the weird message senders on the dating site. They eventually managed to identify all but a small number of the senders. Unlike senders and receivers models, OIT stands on the situational perspective.