I use my Gmail inbox to monitor and use all my emails, including an old Hotmail address.
I've added this address with a POP3 interface under "Check email from other accounts" in my Gmail settings.
All went fine until yesterday I've activated 2FA on my Hotmail account. Since then Gmail reports an unspecified "Authentication error".
How can I solve this? Should I change something in the Gmail options? Or in the Hotmail/Outlook.com ones? Which in particular?