EDIT I realized that this question didn't make sense and is in the wrong section... I updated it
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I currently have people registering to multiple events and I would like to send emails to all the users previously registered to the events. As of now when I email multiple groups, users that have registered to multiple events will receive duplicate emails (one for each event they registered to).
If I were to use your acajoom plug in, will duplicate emails subscribe to a acajoom newsletter list if a user registers to multiple events.
Hello. If you sent emails through Acajoom, you'd send from a list of subscribers... which would have no duplicates. That's probably the direction you need to go.