If you see an error next to your Google mailbox, you likely haven't enabled IMAP.
Understanding IMAP
IMAP (Internet Message Access Protocol) is a method to access your mailbox in real-time. It allows us to access replies to emails as they arrive and display them for follow-up actions without delay.
Enabling IMAP for your Gmail mailbox
Login to the Gmail account for which you want to enable IMAP.
Click the gear icon in the top right corner.
Click All Settings.
Click the Forwarding and POP/IMAP tab.
In the IMAP access section, select Enable IMAP. Click Save Changes.
Image guide
Enable IMAP for Gmail account: Navigation
Enable IMAP for Gmail account: IMAP option
Further assistance
If you continue to have an issue, please contact us through our chat support. We'll do our best to fix your mailbox issue.