As you may have noticed, a bug in OpenSSL has been found recently (heise.de - Der GAU für Verschlüsselung im Web: Horror-Bug in OpenSSL). Various messages indicated that the private key of the server could be read.

We reacted of course immediately and updated OpenSSL. So the mailing as well as the web services should run properly and securely again (… until the next bug).

Furthermore some certificates have been updated. This means, you might get (have gotten) a message indicating this. But this is not bad - in fact it is necessary.

If you want to have more explanations about Heartbleed: xkcd.org or heise.de.