since in terms of MAU, Southeast Asia probably represents over 70% of that
US & Canada is the biggest region for revenue though. This is public info if you look at the slides from the most recent earnings call: https://investor.atmeta.com/investor-events/event-details/2024/Q3-2024-Earnings-Call/default.aspx
FastMail has been around a long time and they’re very good. MXRoute is good too and lets you have unlimited email addresses at an unlimited number of domains (they only limit it based on storage space)