SMTP Emails are not working after an upgrade from 2.3 -> 2.4

[freddyvega]

Sending email with Test Result link does not work on a system that had 2.3 installed and then was upgraded to 2.4
The following is displayed in the server log:
{"message":"101057795:error:14082174:SSL routines:ssl3_check_cert_and_algorithm:dh key too small:openssl\ssl\s3_clnt.c:3615:\n","stack":"Error: 101057795:error:14082174:SSL routines:ssl3_check_cert_and_algorithm:dh key too small:openssl\ssl\s3_clnt.c:3615:\n\n at Error (native)","stage":"starttls","level":"info","timestamp":"2016-06-23T16:41:11.372Z"}

Did something change in the implementation of SMTP emails between the two versions?

[freddyvega]

If I launch RHQ using downgraded cyphers:
node --tls-cipher-list="EXP-EDH-RSA-DES-CBC-SHA" app.js
(see [http://stackoverflow.com/questions/35984308/node-js-openssl-error-dh-key-too-small])

Then SMTP emails are correctly sent. Still trying to figure out if the change was in RHQ's implementation or my SMTP servers.