Zoho actually has a free plan for up to 5 users, including a single custom domain. However, they force you to use their web/mobile mail app unless you upgrade t

Zoho actually has a free plan for up to 5 users, including a single custom domain. However, they force you to use their web/mobile mail app unless you upgrade to their paid plans which include IMAP/POP and many custom domains. Their paid plans are very reasonable and start out at $1 and $1.20 (5/10GB respectively) a month. Recently compared Google, Office 365, Proton, Tutanota, Skiff, and Zoho. Surprisingly ended up with Zoho. Actually a decent experience so far, they've definitely upgraded their stack for the better from what I remember it was a decade ago.