With iOS upgrades Apple is upgrading all apps so does the mail app. Mail app is great mail features and easy to use with different mail types like Gmail, Yahoo, iCloud, Aol, Outlook and Other custom mail server. But after the upgrade mail app is facing many issues.
iPhone 7/8 , iPhone X and an iPad Air 2 user after upgrading to iOS 11.2 are not able the use the mail app anymore on both type of devices, as it always crashes at the start. Even trying to delete and add the account did not help to fix the mail app crash on iPhone. The issue is reported with exchange server like msn.com, outlook.com etc. The mail app on iOS 11 crashes even before opening and this is very frustrating. Apple don’t have comments on this so far.
Workaround for the issue :
You must not add an outlook.com/other mail server account under accounts, you have to choose other. This won‘t use the predefined outlook settings, but at least Mail works without crashing. But it looks like push isn‘t available with this method.