Not That Gary / Ryanair
Easy solution for "not that Gary" - as others have pointed out here at this forum
Contact the real Gary. If he is a resident or citizen of one of the EU countries, get him to report the incident to his country of residence, citing that country's GDPR (General Data Protection Regulation) legislation.
When Ryanair finishes paying the typically hefty fine, they may see fit to upgrade their message delivery system.
Here below is a link to a summary article on GDPR
"How the EU’s GDPR (General Data Protection Regulation) impacts your business"
https://wp.me/pzzpB-S4