Gmail

Google have changed their authentication requirements for Google Mail mail accounts configured for password authentication - and for non-Google mail clients, now requires use of an App Specific password for each mail client/device. 

You will need to generate a unique password for your iPad Gmail account - that will differ from your normal Google Account Password. AOL, Yahoo, Google, Microsoft now all use App Specific Passwords when using anything other than their own email client Apps.

If you need to generate an App Specific Password, you’ll need to log-in to your Google Account management webpage - using a web browser - and generate the Password from the appropriate account security page.

More information can be found here:

https://support.google.com/mail/answer/185833?hl=en-GB

backdam7989 wrote:

Has anyone lost their Gmail access on their iPad, as a result of changing their Gmail account password on their iMac..?

Did you update the password on the ipad as well? If not do so.

backdam7989 wrote:

google blocked attempt to change pw on iPad Auth error 403...disallowed_useragent...

Delete and re-add the account