Helm users receiving calendar invitations from Google will receive an error message if they try to accept the invite by clicking on a response in the email as shown here.
This is because Google is attempting to send an email to the invite creator on the behalf of the Helm user (an email from Google's servers saying that they were firstname.lastname@example.org). Due to Helm's secure and restrictive DMARC policy, this isn't allowed.
The Delivery Status Notification (Failure) will show the following information:
When you receive a calendar invitation from Google, accept the invitation by doing the following:
- In the email invite, open the .ics attachment.
- Accept or reject the calendar invite from the calendar app you are using.
This will ensure that your responses to the invite are delivered in a manner that they pass email authentication checks.