4SecureMail vs Proton Mail
| 4SecureMail | Proton Mail | |
|---|---|---|
| Free plan | No | Yes |
| Free trial | No | No |
| Paid from | — | Free |
| Open source | No | No |
| Platforms | Web | Web, Windows, macOS, Linux, iOS, Android |
| Free plan | No | Yes |
| Paid from | 8.24 /mo | — |
| Encryption scope | transport_only | — |
| Custom domains | Yes | — |
| Mailbox storage | 0.5 GB | 15 GB |
| Email aliases | 3 aliases | 10 aliases |
| IMAP support | Yes | — |
| Private calendar | No | — |
Both are listed in Best Private Email Services. On Inferse, Proton Mail scores higher on our published basis.