List of questions and answer that may be helpful before contacting Qualtrics Support
I can't find anywhere in the Help pages that indicates whether there is an optimal or upper limit on the number of addresses that can be in a panel that is used by the onboard emailer.
While there is no hard limit on panel sizes, we recommend that Panels are no larger than 10,000 panel members. Further, it is a good idea to keep a panel size below 16MB in size to prevent potential issues.
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