>On 27/05/16 02:20, Matus UHLAR - fantomas wrote:
>>> Some lame govt mailservers are still using SSL23...
>>> "SSL23_GET_SERVER_HELLO:tlsv1 alert decode error"
>>> and rather than whitelist them I'm sure I used to just disable SSL
>>> via /etc/courier/esmtpd altogether (currently using v0.68.2)...
>>
>> why not whitelisting? Why to avoid security just because some can't
>> cope with it?

On 27.05.16 13:07, Mark Constable wrote:
>We only use authenticated relaying via 465/SSL and 587/TLS so none
>of our clients use port 25 for auth/relay. The problem is our client
>recipient has to contact our support which then asks them for a copy
>of the error, then I get it, then I have to squirrel around in the
>mail logs to determine IP/hosts and hope a dig mx finds the right
>mailserver etc then whitelists that server/mx and cross my fingers
>I got all that right and our client can continue on their merry way.

Aha... doesn't couriertls produce an error when too low tls version is tried
by the client?

>I don't know how to check what percentage of port 25 mailserver to
>mailserver connections may be SSL encrypted to justify leaving SSL
>on port 25 for server to server connections. Would you (or anyone)
>have any idea how many mailservers are successfully connecting to
>each other via SSL these days?

% grep relay= /var/log/mail | grep sm-mta | grep -c STARTTLS=server
261
% grep relay= /var/log/mail | grep sm-mta | grep -c from=
1007

% grep relay= /var/log/mail.1 | grep sm-mta | grep -c from=
1349
% grep relay= /var/log/mail.1 | grep sm-mta | grep -c STARTTLS=server
296

that gives some 25%

-- 
Matus UHLAR - fantomas, uh...@fantomas.sk ; http://www.fantomas.sk/
Warning: I wish NOT to receive e-mail advertising to this address.
Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu.
They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety. -- Benjamin Franklin, 1759

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