Hot answers tagged email
As I understand this, the problem is that your OpenSSL upgrade has made you intolerant of other's short DH key lengths, in order to protect the conversation against the Logjam attack. That's why increasing your DH key length (openssl dhparam ..., etc.) did nothing to help, whilst turning off TLS did. Obviously, what we'd all like is a flag to OpenSSL like ...
This is more than likely the case. Most providers have in effect a spam and virus filter, so before the original email is delivered it will be caught and discarded / not forwarded. Is this an IP address dedicated to you? If not, others using the IP address (example case, shared hosting) may be contributing towards the negative reputation.
You also need to be sure you have valid DKIM and SPF records setup for your domain. You can create a TXT record that looks like this: google._domainkey So fully resolved that would be google._domainkey.yourdomain.com. Now for DKIM, you need to find your key in googles admin dashboard for your email: v=DKIM1; k=rsa; t=y; ...
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