Mailbird is heavily focused on bringing the best email client to businesses that increase productivity but also make it easy to get through your email workflow daily. There are a few differences for Mailbird Business vs Mailbird Personal at this time but we are likely to add features to the business version in the near future that will no be available for the personal use, Mailbird Personal version.
You can see the feature comparison here: https://www.getmailbird.com/pricing/ (below on the page, underneath the pricing)
Apart from the business apps integrations, Mailbird Business is covered under our terms of service for commercial use. Mailbird Personal is for personal use.
Mailbird Business Customers get 24/7 priority support from our customer happiness team. You get moved to the top of the queue.
Mailbird Business customers are assigned a dedicated account manager.