Recently I have encountered a problem related to the import of contacts and has to do with the dedupe rules.
When you import a list of contacts through a CSV file and select a dedupe rule, the CRM seems to ignore that rule and go directly to use the 'Unsupervised' rule.
For example, if there is a user with mail firstname.lastname@example.org and you use a 'General' rule with the Weight Threshold and the Weight of 10 in email but in the 'Unsupervised' rule the weight is 10 and the Weight Threshold is 15, the mail would be introduced in the CRM even if the rule that was chosen was the 'General'.
This behavior also happens in dmaster.
Is there any reason to prioritize the 'Unsupervised' rule to the rule you have chosen to perform the import?
After more tests I have been able to conclude the following:
Importing data: Name, Last name and email and selecting the skip option.
A) Name (10) Last name (10) Treshold (30) B) Email (10) Treshold (10)
C) Name (10) Last name (10) Treshold (20) D) Name (10) Last name (10) Mail (5) Treshold (25)
A + C = duplicate entry. If the general rule would have been applied correctly should not been duplicated, just skipped.
A + D = duplicate entry.
B + C = skip the entry (works fine)
B + D = skip the entry (works fine)
So as Jon G - Megaphone Tech said, the unsupervised dedupe rule always run, and from there, run your dedupe as well.
So the import first check the unsupervised rule and if the Treshold is greater than the weight of the fields always will import the contact independently the general rule you select.