Special characters not supported in Email addresses
Some special characters are not supported in users email addresses.
An example of this is the character: '
Characters like this are also not supported in various mailing applications, such as GMail or Outlook.
If you find a user with this address, then you can ask for an alternative address without a special character, or create a temporary email address, or create a fake logon and provide the logon and password manually to the user.