Unfortunately, the email delivery is a bit flakey. We like to call it email roulette.
We’re not sure why, but it seems like the Verizon servers get backed up from time to time. Some of the messages get super delayed and others get dropped. If you got an error message, check the “to” address (it should be your_phone_number@vzwpix.com) and try it again. It should eventually work.
Good luck. We hope to be able to send messages directly to Verizon phones again soon.