Some email providers have a two-factor authentication feature to increase security. Once enabled, your provider sends a notification to the mobile device of your choice.
If your email inbox is set to require two-factor authentication, you will see the message "Unauthorized. Please check the email address and password and try again" when attempting to connect your inbox to HubSpot using IMAP:
You'll need to generate a third-party app password from your email provider in order to connect your inbox to HubSpot. Learn how to do this for the following major email providers:
Please note: Gmail users can simply use the native integration with HubSpot – you don't need to use IMAP with an app-specific password.
Read more about this on the Community.