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Error code: ssl_error_no_cypher_overlap

If you are receiving the following error:

Error code: ssl_error_no_cypher_overlap

Then this means that your mail server does not support the cipher encryption set supported by Postbox. When Postbox connects to your server, it responds with a list of ciphers it supports. Postbox also has a list of ciphers it supports, and will attempt to pick the best cipher that is common to both the email server and Postbox.

This error indicates that no common ciphers were found across both lists, and this usually happens in older, not very well maintained email servers.

Our recommendation is to work with your email provider in getting a more modern set of ciphers supported on the email server.

For IT managers, here is a list of ciphers that Postbox supports:

TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 (0xc02b)
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (0xc02f)
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (0xc00a)
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (0xc009)
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (0xc013)
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 (0xc023)
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 (0xc027)
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (0xc014)
TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA (0xc008)
TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA (0xc012)
TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 (0x9e)
TLS_DHE_RSA_WITH_AES_128_CBC_SHA (0x33)
TLS_DHE_DSS_WITH_AES_128_CBC_SHA (0x32)
TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 (0x67)
TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA (0x45)
TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA (0x44)
TLS_DHE_RSA_WITH_AES_256_CBC_SHA (0x39)
TLS_DHE_DSS_WITH_AES_256_CBC_SHA (0x38)
TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 (0x6b)
TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA (0x88)
TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA (0x87)
TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA (0x16)
TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA (0x13)
TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA (0xc004)
TLS_ECDH_RSA_WITH_AES_128_CBC_SHA (0xc00e)
TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA (0xc005)
TLS_ECDH_RSA_WITH_AES_256_CBC_SHA (0xc00f)
TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA (0xc003)
TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA (0xc00d)
TLS_RSA_WITH_AES_128_GCM_SHA256 (0x9c)
TLS_RSA_WITH_AES_128_CBC_SHA (0x2f)
TLS_RSA_WITH_AES_128_CBC_SHA256 (0x3c)
TLS_RSA_WITH_CAMELLIA_128_CBC_SHA (0x41)
TLS_RSA_WITH_AES_256_CBC_SHA (0x35)
TLS_RSA_WITH_AES_256_CBC_SHA256 (0x3d)
TLS_RSA_WITH_CAMELLIA_256_CBC_SHA (0x84)
TLS_RSA_WITH_SEED_CBC_SHA (0x96)
SSL_RSA_FIPS_WITH_3DES_EDE_CBC_SHA (0xfeff)
TLS_RSA_WITH_3DES_EDE_CBC_SHA (0xa)