TABLE 4.
Confounding matrix of mail user agent (MUA) and encryption technology including the number of tests made.
| Mail user agent | PGP | S/MIME | pEp |
|---|---|---|---|
| Apple mail (iOS 12) | - | 1 | - |
| Apple mail (MacOS desktop) | - | 1 | - |
| Flowcrypt (gmail webmail) | 2 | - | - |
| Maildroid (Android) | 1 | 1 | - |
| Outlook 2016 (desktop) | 1 | 4 | - |
| pEp app (Android) | - | - | 4 |
| Thunderbird (desktop) | 1 | 2 | 6 |
| Total | 5 tests with 4 MUAs | 9 tests with 5 MUAs | 10 tests with 2 MUAs |