[Admin] Action required: New feature and your Let's Encrypt integration

Starting Feb. 19, 2020, Let's Encrypt began making multiple domain validation
requests from diverse network vantage points. More info here:
https://community.letsencrypt.org/t/acme-v1-v2-validating-challenges-from-multiple-network-vantage-points/112253

We are excited to be able to turn on this feature with little to no
interference with your integration. We expect this feature to affect less than
1% of all domain validations from the Let's Encrypt certificate authority.
That's better security, by default, for you and your customers.

Your ACME account ID 6197113 may have some errors and failed validations
due to the multiple vantage point validation feature. We suggest you monitor
your implementation when the feature is turned on and make any fixes necessary.

In case you're having trouble locating your affected system(s): your ACME
account recently requested a certificate on 2019-12-24 for:
io.ffnw.de

The best way to test compatibility for this feature is to perform test
issuances in our staging environment where the new requirement is already
enabled: https://letsencrypt.org/docs/staging-environment/

Exception:

If you need extra time to work on getting your integration ready for multiple
vantage point validation, we will have an exception list available through June
1, 2020: https://forms.gle/9QN7dxALJVAoRjMKA

This exception list is temporary. After June 1, 2020, you will be using the
multiple vantage point feature and may experience increased domain validation
failure rates unless you take action to ensure compatibility.

Getting Help:

Our expert community, including Let's Encrypt staff and many client developers,
monitor our community forum and are available to help if you get stuck.
https://community.letsencrypt.org/

The best way to keep up-to-date on this new feature (and all API-related Let's
Encrypt announcements) is to subscribe to our API announcements by clicking the
bell in the top right corner of this page:
https://community.letsencrypt.org/c/api-announcements/

Best,

The Let's Encrypt Team

If you are receiving this email in error, unsubscribe at:
  http://mandrillapp.com/track/unsub.php?u=30850198&id=ce801217b136400c8f2f7845c8c15acd.5TBEhaGhdzuJdBOHedb9lcRIUJc%3D&r=https%3A%2F%2Fmandrillapp.com%2Funsub%3Fmd_email%3Dadmin%2540lists.ffnw.de
Please note that this would also unsubscribe you from other Let's Encrypt
service notices, like expiration reminders.