The other thing is overengineering. Spending a week to implement email validation? Maybe, if it is REALLY important and results in lost revenue. Otherwise I do

The other thing is overengineering. Spending a week to implement email validation? Maybe, if it is REALLY important and results in lost revenue. Otherwise I don't know what common typos are. I would have to do research on that. Then I have popular local email providers where I may come up with typos. but then again, it is only in my region - I would have to get some list of popular email providers in every country. Come up with a way to update that list after few years when new email providers come out. Or maybe develop a solution that matches "close enough" entries in my pre-defined list. UX effort could be spent in an area which is used more often than only once. If there is a library for that, yeah, then slap it in, UX has been upgraded in no time. And again, only if revenue is on the other side of consideration, the development effort pays off.