Allow access for less secure apps ?

Double check that access is allowed for "less secure apps".  (This simply means that third-party applications like Tamago-DB are allowed to connect to your account.)

  1. Go to Google Security (Less Secure Apps)
  2. "Turn on" access for less secure apps

Note that you will need to speak to your domain administrator (whoever sat the email address) to turn on the access for less secure apps.

2-Step Verification enabled ?

If you are using 2-Step Verification with Gmail or Google Apps, you will have to generate an "app password" and use that to sign-in.

Generating an app password is a simple three step process:

  1. Login to app passwords page to see your list of app passwords
  2. At the bottom of the page selection your application and device.  Click "Generate" to create a random app password.
  3. A new password will appear in a yellow bar.  Follow the instructions to add this password to your the application on your device to login.

If necessary, this password can be revoked from app passwords at any time.

Make sure your mailbox is set to allow IMAP access

Make sure IMAP is generally enabled for your Gmail account.

Remove the IMAP folder size limit 

In the 'Forwarding and POP/IMAP', set the 'Folder Size Limits' to 'Do not limit'.

Enable labels to be accessed by IMAP

Usually IMAP is active for the "All Mail" label, however in some cases it can become disabled.  Ticking the corresponding checkbox will ensure that we can index all emails regardless of whether they have been archived or moved to different folders/labels.