I just received an email from mailbox.org saying that they will no longer support push notifications for iOS Apple Mail. Unfortunately, it hasn’t worked reliably for some time.
Dear customers of mailbox.org,
We would like to inform you that we will deactivate the service for
providing push notifications for Apple Mail iOS via the
community-developed tool dovecot-xaps-daemon on Thursday, 26 June 2025.
The reason for this is that the necessary APNs certificates for the
alternative XAPS implementation will expire on Friday, 27 June 2025 and
will not be renewed by Apple. Without these certificates, it will no
longer be technically possible to operate the service.
Email use on Apple devices will of course remain possible - only the push
delivery of new messages via the Apple Push Notification System (APNs)
will be cancelled. We recommend that affected users adjust the retrieval
interval in their mail app (e.g. “every 15 minute”) in order to continue
to be regularly informed about new emails.