I would blame Tapatalk. SMF allows you to choose to receive notifications, or not. I have no idea how Tapatalk works, but if it's intercepting how SMF sends them in order to send you push notifications and you get the original from SMF and also whatever Tapatalk adds, it's hardly the forum software's fault, and there is likely nothing we can do about it.
On your end, depending on which email you use, you could probably set up a filter to make them shut up in your inbox: gmail allows for custom filters which can be handled any number of ways: mark as read, label, send to folder, archive, delete, etc.
