Welcome Email not Sending


So years ago i created a database of users. Now I created several split databases, and would like to publish it. the only problem is if a user has subscribed to my first database, they will no longer getting the Welcome Email. They will only get the confirmation URL, and once their subscription has been confirmed (the new and the old one), they never get the Welcome Email.

Is there any way to make them get the Welcome Email without resorting to delete the first database?

Thank you.