To allow programs such as ZeyOS or Outlook to connect to your Gmail account, permission must be set for it under Gmail.
Sign in to Gmail and go to Settings.
Select the tap Forwarding and POP/IMAP and Enable IMAP.
Save your canges.
Find further detais at https://support.google.com/mail/troubleshooter.
Stay logged in at your Gmail account and go to https://myaccount.google.com/intro/security.
At Sign-in & security select Connected apps & sites.
Change the setting Allow less secure apps: to on
Since we reduced safety standard in the previous step, we are going to raise safety standard again by activating 2-step verification. This also facilitates ZeyOS to connect to Gmail.
First go to https://myaccount.google.com/intro/security at Sign-in & security select Signing in to Google.
At Password & sign-in method activate 2-Step Verification.
Please follow the instructions. As soon as 2-step varification is active, you need to generate an app password
Go to Sign-in & security, select Signing in to Google and choose App passwords
At select app please select Other (Custom name). Now name your app e.g. 'ZeyOS'
Note down your 16-character app password or leave the browser tab open. You will need this password in your mail server settings at ZeyOS.
Now Gmail is prepared to work with ZeyOS and you can install it. Here you can find how it works in ZeyOS:
Please mind to use the generated App password instead of your Gmail password.