How to sign-in on iPhone using an email that contains an apostrophe?

Valid emails can contain an apostrophe which is part of a first or last name and users with iPhone iOS 11 or later will get a sign-in error

If you are trying to sign-in using an iPhone with iOS 11 or later and you have an apostrophe character in your email address then you will get a sign-in error due to the smart punctuation feature, where Apple uses 3 different apostrophe characters for app sign-ins.

Left quote mark ߵ
Right quote mark ߴ
vertical apostrophe '

example email addresses that can contain an apostrophe

john.o'connor@acme.com, simon.o'leary@acme.com, tina.o'brien@acme.com

Possible Remediation options to this issue are as follows:

Remediation Option

Description

One time fix - Paste the email address using the vertical apostrophe

Type out your email address in another app on your iPhone (e.g. notes or similar) and make sure it contains the vertical apostrophe e.g. john.o'conner@acme.com
Copy the email address, then open the Forget Me Not App
At the Sign-in screen, paste the address instead of typing it and then enter the your password.

Permanent Fix - Disable smart punctuation
Note: Disabling smart punctuation will impact all other apps

To turn Smart Punctuation off

Tap Settings > tap General.
Then, tap Keyboards, and toggle Smart Punctuation to off