If you’re using Gmail or GSuite it might throw some errors, check below for a solution:
- If you have 2-factor authentication enabled (almost all have this enabled) then create an app password for pos.
- More details here https://support.google.com/accounts/answer/185833?hl=en
- Create app password from here: https://myaccount.google.com/apppasswords
- Change port & encryption: Try using port 465 and encryption SSL
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