Last week (May 6 approx to date), some of the emails i used to send (successfully) failed in rendering in outlook mobile. I haven’t changed anything in the html code. I want to know if outlook changed its rendering rules and if ther’s somewhere i can check for these kind of changes. Thanks!

I’ve solved the problem, by making a few changes in the code. But i need to underestand what had happened, why, and explain this to the team members. That’s why i need some paper to backup what i think had happened.