Supported Ciphers by Our SMTP Servers.

Your server can connect to ImprovMX servers by encrypting the connection using TLS or STARTTLS.

In order to be compatible, we support a broad set of ciphers and protocols, which range from SSLv3 to TLSv1.3.

Here's the full list:

SSLv3

ADH-AES256-SHA
ADH-CAMELLIA256-SHA
ADH-AES128-SHA
ADH-CAMELLIA128-SHA
SRP-DSS-AES-256-CBC-SHA
SRP-RSA-AES-256-CBC-SHA
SRP-AES-256-CBC-SHA
RSA-PSK-AES256-CBC-SHA
DHE-PSK-AES256-CBC-SHA
AES256-SHA
CAMELLIA256-SHA
PSK-AES256-CBC-SHA
SRP-DSS-AES-128-CBC-SHA
SRP-RSA-AES-128-CBC-SHA
SRP-AES-128-CBC-SHA
RSA-PSK-AES128-CBC-SHA
DHE-PSK-AES128-CBC-SHA
AES128-SHA
CAMELLIA128-SHA
PSK-AES128-CBC-SHA

TLSv1.0

ECDHE-ECDSA-AES256-SHA
ECDHE-RSA-AES256-SHA
AECDH-AES256-SHA
ECDHE-ECDSA-AES128-SHA
ECDHE-RSA-AES128-SHA
AECDH-AES128-SHA
ECDHE-PSK-AES256-CBC-SHA384
ECDHE-PSK-AES256-CBC-SHA
RSA-PSK-AES256-CBC-SHA384
DHE-PSK-AES256-CBC-SHA384
ECDHE-PSK-CAMELLIA256-SHA384
RSA-PSK-CAMELLIA256-SHA384
DHE-PSK-CAMELLIA256-SHA384
PSK-AES256-CBC-SHA384
PSK-CAMELLIA256-SHA384
ECDHE-PSK-AES128-CBC-SHA256
ECDHE-PSK-AES128-CBC-SHA
RSA-PSK-AES128-CBC-SHA256
DHE-PSK-AES128-CBC-SHA256
ECDHE-PSK-CAMELLIA128-SHA256
RSA-PSK-CAMELLIA128-SHA256
DHE-PSK-CAMELLIA128-SHA256
PSK-AES128-CBC-SHA256
PSK-CAMELLIA128-SHA256

TLSv1.2

ECDHE-ECDSA-AES256-GCM-SHA384
ECDHE-RSA-AES256-GCM-SHA384
ECDHE-ECDSA-CHACHA20-POLY1305
ECDHE-RSA-CHACHA20-POLY1305
ECDHE-ECDSA-AES256-CCM8
ECDHE-ECDSA-AES256-CCM
ECDHE-ECDSA-ARIA256-GCM-SHA384
ECDHE-ARIA256-GCM-SHA384
ADH-AES256-GCM-SHA384
ECDHE-ECDSA-AES128-GCM-SHA256
ECDHE-RSA-AES128-GCM-SHA256
ECDHE-ECDSA-AES128-CCM8
ECDHE-ECDSA-AES128-CCM
ECDHE-ECDSA-ARIA128-GCM-SHA256
ECDHE-ARIA128-GCM-SHA256
ADH-AES128-GCM-SHA256
ECDHE-ECDSA-AES256-SHA384
ECDHE-RSA-AES256-SHA384
ECDHE-ECDSA-CAMELLIA256-SHA384
ECDHE-RSA-CAMELLIA256-SHA384
ADH-AES256-SHA256
ADH-CAMELLIA256-SHA256
ECDHE-ECDSA-AES128-SHA256
ECDHE-RSA-AES128-SHA256
ECDHE-ECDSA-CAMELLIA128-SHA256
ECDHE-RSA-CAMELLIA128-SHA256
ADH-AES128-SHA256
ADH-CAMELLIA128-SHA256
RSA-PSK-AES256-GCM-SHA384
DHE-PSK-AES256-GCM-SHA384
RSA-PSK-CHACHA20-POLY1305
DHE-PSK-CHACHA20-POLY1305
ECDHE-PSK-CHACHA20-POLY1305
DHE-PSK-AES256-CCM8
DHE-PSK-AES256-CCM
RSA-PSK-ARIA256-GCM-SHA384
DHE-PSK-ARIA256-GCM-SHA384
AES256-GCM-SHA384
AES256-CCM8
AES256-CCM
ARIA256-GCM-SHA384
PSK-AES256-GCM-SHA384
PSK-CHACHA20-POLY1305
PSK-AES256-CCM8
PSK-AES256-CCM
PSK-ARIA256-GCM-SHA384
RSA-PSK-AES128-GCM-SHA256
DHE-PSK-AES128-GCM-SHA256
DHE-PSK-AES128-CCM8
DHE-PSK-AES128-CCM
RSA-PSK-ARIA128-GCM-SHA256
DHE-PSK-ARIA128-GCM-SHA256
AES128-GCM-SHA256
AES128-CCM8
AES128-CCM
ARIA128-GCM-SHA256
PSK-AES128-GCM-SHA256
PSK-AES128-CCM8
PSK-AES128-CCM
PSK-ARIA128-GCM-SHA256
AES256-SHA256
CAMELLIA256-SHA256
AES128-SHA256
CAMELLIA128-SHA256

TLSv1.3

TLS_AES_256_GCM_SHA384
TLS_CHACHA20_POLY1305_SHA256
TLS_AES_128_GCM_SHA256