Magento has announced that they will 'd stop supporting the Magento 1.x platform, and will has finally sunset the version 1 by on June 2020. More info info here.
Following this announcement, we will stop have stopped supporting our integration with Magento 1 as well. Support ended on June, 30 2019.
When you configure the MailUp extension for Magento, you can indicate how often you want the system to gather customer data and pass it to MailUp.