Gmail IMAP telling me to "please log in using your web browser"

Question

I've started using an organizational Gmail account (i.e. [email protected] where myorg has a Google Applications subscription or whatever it is they call it).

Now, I can log in via the web and read my email and that's all fine. However, if I try to log in with IMAP (using the settings Google's support indicates), my login fails, and I get a message saying:

Alert from account [email protected]@gmail.com:
Please log in via your web browser:
http://support.google.com/mail/accounts/bin/answer.py?answer=78754
(Failure)

I went there, and followed the instructions - up to "App Passwords". When I try generating an "App Password", I get a page saying:

The setting you are looking for is not available for your account.

What should I do?

Answer 1

While it may seem counter-intuitive, Google believes your IMAP client is a "less secure application" relative to your web browser. You must therefore

Allow less secure apps: If you don't use 2-Step Verification, you might need to allow less secure apps to access your account.

• Visit https://www.google.com/settings/security/lesssecureapps
• (log in if necessary to get there)
• Flip the switch named "Allow less secure apps" to the ON state.

You should now be able to login via IMAP.