Not a long time user but quite happy with the service and the support; one of the best calendars I have ever used. Quite easy to configure a custom domain.
FastMail is an extremely reliable and easy-to-use product. I have been a happy user of the product for years. Over the past years they have greatly improved the usability and look and feel. I love their strong commitment to security and privacy, but also how they keep embracing open standards.
3.9/5. Certain features are lacking. No end-to-end encryption. Data logging feature does not capture all the data it should, such as inexplicable failure to record every login/logout. Difficult to edit text styling in messages. Calendar integration has improved but still leaves one desiring more. Perhaps the most significant issue is pricing. It is more expensive for less storage and features than one can obtain through myriad email services.
Reliable, fast, have notes, calendars, filters, masked emails, and a lot of tiny features here and there I use daily. It perfectly does the job for me and is worth the price.
Fastmail has great features, and it's easy to use. I avoid Gmail because I don't like how much data Google tracks and analyzes. I switched from iCloud mail because Fastmail has better email rules, better junk mail filtering, and Masked Email. The Fastmail Notes feature is also surprisingly handy.
I've just moved from iCloud to Fasmail because of search (which includes PDF indexing), the integration with 1Password for masked addresses using my domain and labels. I miss a native iOS app, though. The current app isn't pretty and visually buggy, and Fastmail would attract many more customers by adopting native apps instead of using this cross-platform approach that doesn't feel right.