Weird email address characters on both Iphone and Mac

Hi all,

Everyone that uses Mac Mail / Iphone Mail here in my company is receiving weird emails address on both Mac and Iphone. This happens when someone reply to an email with correct address and new received emails as well. We need to borrow all the recipients and input it manually to work. This never happened in 7 years and started 3-4 months ago. I've searched everywhere and can't find a solution for that, nor a possible reason or a standard situation, it happens randomly. Screenshot as example:

Any clue how to fix that? It's really annoying!

Thanks,

Renan