It is sometimes important to know which Email service provider (ESP) is behind an email address:

• It can be a quick way to filter out free email addresses from your database to focus only on B2B contacts.

• Sending emails from Gmail to Gmail and Outlook to Outlook is boosting your email deliverability. For even better results, you can use an ESP warmup tool.

• You can optimize the copy of your email to align with how each ESP displays emails.