Enable IMAP for Gmail inbox

Step 1. Go to Gmail inbox and click on the settings icon on the top right corner.

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Step 2. Click on "See all settings" button.

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Step 3. Select "Forwarding and POP/IMAP" tab in the settings page.

gmail_imap_settings

Step 4. Choose "Enable IMAP" option under IMAP access section and click on "Save Chabges" button.

gmail_enable_imap