| Comparison of the method | ZT Browser | ZoTrus Email Gateway | Other Email Client | TLS Email Encryption | 
|---|---|---|---|---|
| S/MIME certificate encryption | NO | |||
| Auto-configure email certificate | No, apply and configure manually  | 
NO | ||
| Email transmission always encrypted | Yes,  both sides must support TLS  | 
|||
| End-to-end email encryption | NO | |||
| Ciphertext stored on the mail server | NO | |||
| Digital signature proves trusted identity | NO | |||
| Timestamp certifies the email sent time | NO | |||
| Key management | In device and mailbox  | 
In Gateway, central management  | 
NO | NO | 
| Need to replace the email client | No, but need to use ZT Browser  | 
NO | NO | |
| Need to purchase the email gateway | No | No | No | |
| Support SM2 algorithm | No | Yes, if using SM2 SSL certificate  | 
||
| Applicable scenarios | All | Key central management | End-to-end encryption | Minimum requirements |