Have a look at the MIB:
hm2LogEmailClientTlsCipherSuites OBJECT-TYPE
SYNTAX       Hm2TlsCipherSuites
MAX-ACCESS   read-write
STATUS       current
DESCRIPTION " The cipher suite supported by the email-alert logging client."
DEFVAL       {{
                     tls-dhe-rsa-with-aes-128-cbc-sha,
                     tls-ecdhe-rsa-with-aes-128-cbc-sha,
                     tls-ecdhe-rsa-with-aes-128-gcm-sha256
}}
::= { hm2LogEmailAlertGroup  19 }
Hm2TlsCipherSuites ::= TEXTUAL-CONVENTION
       STATUS       current
       DESCRIPTION  "The Transport Layer Security ciphers available on the device."
       SYNTAX       BITS {
                           tls-rsa-with-rc4-128-sha(0),
                           tls-rsa-with-aes-128-cbc-sha(1),
                           tls-dhe-rsa-with-aes-128-cbc-sha(2),
                           tls-dhe-rsa-with-aes-256-cbc-sha(3),
                           tls-ecdhe-rsa-with-aes-128-cbc-sha(4),
                           tls-ecdhe-rsa-with-aes-256-cbc-sha(5),
                           tls-ecdhe-rsa-with-aes-128-gcm-sha256(6),
                           tls-ecdhe-rsa-with-aes-256-gcm-sha384(7)
                    }