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_{(1) New recipients are added to list when a message is sent to them
(2) For this API the feature is designed for bulk operations, its massive use on single recipients may affect system performances
(3) New recipients are added when listed in enclosed "one2may.import" file
(4) Requires a customization
(5) Can be used for confirmation requests, not for massive use (see this Rate Limiting about SendSingleNewsletter)
(6) With the "Text message (SMS) sending from .CSV file" feature}

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Use cases

Synchronize recipients between your application and MailUp

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