I'm using CiviCRM with Wordpress and have around 1500 contacts.
I have 3 groups with around 120 contacts in each group which I use for mailings.
I sent a bulk email to one of the groups then around 10 minutes later all 3 groups had 550 contacts in them.
When I look in the Groups tab of one of the newly added contacts I can see that they were added to all 3 groups at the same time and says "Added (by Admin)".
Has anyone come across this before or have any idea why it might have happened?
Is there a way to find contacts based on date added to a group so I can search for them and remove them from the groups?