Messages in this context is information being sent to the server. So it has most likely picked up a backlog of 'messages' because you lost connection to the server and then continued to press buttons. The message from ZOS doesn't relate to you sending actual in game messages to other players.
Try reloading UI, closing down the game and doing a hard reset on your PS4 and check your internet connection on another device. I always turn off my PS4 after a session unless I'm downloading something on rest mode. It seems to help completely shutting down rather than rest moving after playing ESO.
PUG Life - the true test of your skill
18 characters, 17 max level, at least 1 Stam and 1 Mag of every class, 1 of every race and 1200+ CP
Tanked to Undaunted 9+ Mag and Stam of every class using Group Finder for 90+% of the Vet Dungeon runs
I'll try completely shutting it down but I shut it down completely every day as it is. Good to know it is spamming chat or something. Don't want to annoy my guildmates with dozens of repeat messages all firing at once.
Internet is great and at full strength on my other devices. I started having chronic internet issues with this game within the last few weeks. Everything worked peachy before that except the occasional blip here and there.