Open the Mailbird menu (three horizontal lines in the top-left corner). Go to > About Mailbird .

If you want, I can:

: Manage every Gmail, Outlook, or IMAP account in one unified inbox.

See exactly when your messages are opened in real-time.

: Depending on your plan (Standard vs. Premium), your license key allows you to sync your settings and accounts across multiple Windows and Mac devices. How to find my Mailbird License Key

For the uninitiated, Mailbird is widely considered one of the best email clients for Windows. It aggregates all your inboxes (Gmail, Outlook, Yahoo, AOL, and hundreds of IMAP accounts) into a single, unified feed.