with gmail for smtp... less secure apps warning

In general settings, when configuring an outgoing email server, if you try to use a brand new gmail account and then press the test button you get the following warning in your gmail inbox.

smtp.gmail.com
465
SSL/TSL

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Hi John,

We recently blocked a sign-in attempt to your Google Account [<email address hidden>].

Sign in attempt details
Date & Time: Saturday, August 16, 2014 6:02:05 PM UTC
Location: Port Dover, ON, Canada

If this wasn't you
Please review your Account Activity page at https://security.google.com/settings/security/activity to see if anything looks suspicious. Whoever tried to sign in to your account knows your password; we recommend that you change it right away.

If this was you
You can switch to an app made by Google such as Gmail to access your account (recommended) or change your settings at https://www.google.com/settings/security/lesssecureapps so that your account is no longer protected by modern security standards.

To learn more, see https://support.google.com/accounts/answer/6009563.

Sincerely,
The Google Accounts team
This email can't receive replies. For more information, visit the Google Accounts Help Center.