Why the confirmation emails are not delivered to my attendees?
1. Please check the email id registered by the attendee, if it is misspelled or incomplete then the confirmation email may not be delivered.
2. Check your (Organizer’s) email id registered with Eventzilla, The confirmation email will display the organizer's email id as the sender's email id. The deliverability issue is mainly due to the DMARC policy initiative by mail service providers such as Yahoo or AOL.
On checking the above points you can send us an email to firstname.lastname@example.org with the respective order ref no. whose confirmation email has not been delivered.