We have found that many junk contact records have been created in our production instance, with the owner as a system user. These records only have email-id as information and the owner is system user and no more information is filled. We have also opened a case with Microsoft related to this but their solution is also not working.
The solution provided by Microsoft is below. they suggested to turn off the auto-creation of contact. I performed the steps suggested by them but it is still happening.

please help me with this as it creates around 100+ records in a day
Thanks & regards
Subhash Mahato