I didn't go as far as using automated messages with my guests, but

- organised everything, from guests attendance to guests in tables location, in a huge Gsheets with my wife and a few close relatives.

- did a mobile game for Android and iPhone that was a quiz about me and my wife to be with over 200 questions, that still, 2 years later, people still play at and try to get higher in the leaderboard.

- programmed a Raspberry Pi that showed a slideshow of over 500 pictures of us with our guests since like forever. These pictures were also printed and hanged around the venue for them to find them and take them home.

I also did 10 programmes in 10 different programming languages that printed the food menu (to be used as per table printed menus), but my wife wisely thought it wasn't a good idea.