目前这种属性是默认enable的了，在Account Setting里面你可以看到相应的设置。
Email is no longer the only unique identifier in Pardot. Pardot admins can check their account settings page to see whether their account allows multiple prospects with the same email address (AMPSEA). This feature is enabled by default for Pardot accounts created after June 14, 2016.
具体可以参考以下的链接：https://help.salesforce.com/articleView?id=pardot_admin_ampsea_parent.htm&type=0
有几点需要特别说明一下：
1.Prospect Import
Prospect import serves two purposes in Pardot: creating records and updating existing records. You can now use CRM ID (Lead ID, Contact ID, or Person Account ID) as an optional matching criteria for prospect import. Importing by CRM ID is ideal when you import new records from Salesforce, because the new prospects are associated with the Salesforce record upon creation. （在Pardot中Import数据时，有两种结果Create a new record OR update existing records,由于email address已经不能成为我们惟一的标志了，所以我们使用CRM ID来作为另一个规则）
2.Send Email
When you send a list email, Pardot deduplicates by email address. If multiple prospects in the list send have the same email address, Pardot sends the email to the one with the most recent activity. (所以邮件只会发给其中一个Prospect)
