Currently, when a patron chooses to receive digest only notification for hold filled but have no email address, Koha fall back on a print notification. This notification is using the HOLD template, and the request to receive digest is ignored. Multiple notification will be generated if multiple holds are filled. This seems due to the code around https://github.com/Koha-Community/Koha/blob/main/C4/Reserves.pm#L1929 in Koha/C4/Reserves.pm function _koha_notify_reserve #Making sure that a print notification is sent if no other transport types can be utilized. if ( !$notification_sent ) { &$send_notification( 'print', 'HOLD' ); } To reproduce : 1- Choose a borrower, make sure it has : - no email address - patron messaging prefereces : Hold filled : Email and Digests only 2-Create 2 holds for this borrower 3- Checkin document for these holds and confirm the hold each time 4- Go back to the patron page, on the Notices tab, 2 print notification are generated.