I have been asked to implement some email address validation on a web app - I'm sure we've all been there a thousand times... however, this time I have been asked to do an MX Lookup on the domain to see if it accepts emails.
Does anyone know of any potential problems with doing this? Is an mx lookup a reliable way of finding out if a domain accepts email? are there any edge cases where a valid email address could fail an MX lookup check?
Thanks for your advice!