Ok, I am going to try and explain this as best I can:
I am working with nonprofit to help export their donors for last year, but some of the contacts have their own email address listed as well as another individual's email address that is completely unrelated. Sometimes the address information is completely different as well.
It looks like it has been merging/overriding the contacts based on their first names, but it doesn't do that for everyone with the same first name.
They set their event registration duplicate matching rule to "Name and Address (reserved) - General" and I'm think that may have something to do with the merged contacts? My customer isn't manually merging duplicate contacts, so that's where some of the confusion lies as well.
They also have online contributions setup, so CiviCRM is also merging/overriding the information used when making contributions if it's different than what is already showing in the contact record.
Here are a couple of examples:
Billy S recently donated $25 - in his CiviCRM contact record, his home email is listed as email@example.com and personal email as firstname.lastname@example.org
Katherine (Kathy) V recently donated $1,000 online - in her CiviCRM contact record, her home email is listed as email@example.com and her billing email is firstname.lastname@example.org
**In both of these cases the "home email" is incorrect but the personal or billing email is correct.
This example is the one that is actually combining 4 different contacts with the first name of "John", but only one John now exists as a contact in CiviCRM:
John M donated $100 on Oct 30, 2017
John V donated $1,000 on Dec 6, 2017
John W donated $250 on Dec 22, 2017
John R donated $1,000 on Dec 31, 2017 (this is the only contact that is now showing in CiviCRM, but it includes all 4 of those donations)
Each of these donors received their receipts to their own email addresses confirming their contribution.
Now, when we pull a report, only John R's name is listed and he's listed as giving 4 times:
10/30/2017 16:25 - $100.00
12/6/2017 22:21 - $1,000.00
12/22/2017 7:32 - $250.00
12/31/2017 10:35 - $1,000.00
When searching contacts in CiviCRM, John R's name is the only one that comes up. When searching by email addresses, only John R's email "exists" in the system.
So, is this all related to the dedupe rule that has been used for events that these donors have also signed up for?
Or is it something else entirely?
Any assistance with this would be GREATLY appreciated!
And if you need any further clarification, just let me know because I know this is very confusing and difficult to fully explain :)