A: Hello there Hugo,

Thank you for your message. All current users will still be able to continue using Mailbird PayOnce with all existing features. However, this offer doesn't include the cross-platform experience, available only in Mailbird Next. For an upgrade, we plan on offering exclusive deals to all our customers for a cross-platform experience, this is yet a work in progress.

Hope this helps, please let us know if we can be of any further assistance!