[AusNOG] Issues receiving from TPG Mail servers.

[Peter Tonoli]

Quoting Paul Wilkins <paulwilkins369 at gmail.com>:

> One thing you might check is the cipher set you're using.
>
> I can connect to https://tpg.com.au with TLS1.2 just fine.
>
> TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, 256 bit keys, TLS1.2
>
> Output of following can usually highlight problems:
>
> openssl s_client -connect mx1.tpgi.com.au:465
> or
> curl -v smtps://mx1.tpgi.com.au:465

The issue with TLS 1.2 is that it's susceptible to a downgrade attack,  
therefore bringing it down to 1.1/1.0/SSL3.

Cheers,
Peter.