Hello,
Your certificate (or certificates) for the names listed below will expire in 9 days (on 01 Dec 17 21:27 +0000). Please make sure to renew your certificate before then, or visitors to your website will encounter errors.
invoices.ffnw.de
For any questions or support, please visit https://community.letsencrypt.org/. Unfortunately, we can't provide support by email.
For details about when we send these emails, please visit https://letsencrypt.org/docs/expiration-emails/. In particular, note that this reminder email is still sent if you've obtained a slightly different certificate by adding or removing names. If you've replaced this certificate with a newer one that covers more or fewer names than the list above, you may be able to ignore this message.
If you want to stop receiving all email from this address, click http://mandrillapp.com/track/unsub.php?u=30850198&id=9e76a6f162764c708bf... (Warning: this is a one-click action that cannot be undone)
Regards, The Let's Encrypt Team