If you have changed your password and/or locked the account... and you're still getting "Successful Login" emails, then chances are high they are just phishing emails.
To view the original message headers, open the message, click the '...' options button in the top-right corner of the message and then select "Show Original".
edit: https://prnt.sc/nb9uyq
https://prnt.sc/nb9ulx
https://prnt.sc/nb9uqm
Those are screenshots from the last login attempt from Paxful, I've already had like 5 different people access my account anyways, so I don't really care as the password isn't linked to any other social account I have.