[rez9x]

I use ProtonMail because of their good support for custom domains. Their higher focus on privacy and security is nice, but it has little to do with why I chose them vs competitors. The only downside is you have to use the ProtonMail app or website on mobile, because of the way they do mailbox encryption.

[rekoil]

What put me off from ProtonMail was their ridiculous "pay us money for extra domains" charge which makes it obvious to me they are not as honest as I initially thought they were. Allowing me to connect other domains to my one mailbox shouldn't cost them anything beyond the initial costs of developing the code to support multiple domains which they've obviously already done.

[james-redwood]

Even if you pay for the premium service? I thought that was one of the features: where one could use it on a third party mail client.

[arubania2]

That's true for the desktop - they provide an app called the Bridge that logs into your inbox, decrypts the mail and exposes an email service on localhost that you can point your mail client to.