Using Sierra OS. I have a gmail account and i connected it to the mac mail app. I can receive emails just fine but I get this error message when I send a message: https://i.sstatic.net/gKXBW.jpg

I deleted every server on smtp list and added a manual one but it still wont work: https://i.sstatic.net/MZ3o4.jpg

2 Answers 2


Your credentials are not working with gmail. See the suggested gmail help article for troubleshooting. Try logging in with a web browser on your computer first. It may be that 2 factor authentication is causing issues.

  • I have no 2fa on my gmail. At least thats what i know. Already checked everything too if my password is correct. This is so weird. BUT it did send using my work email. Edit: ok i checked and 2fa is off on my gmail
    – J. Mangum
    Oct 23, 2018 at 16:11

Try to enable less secure app access in https://myaccount.google.com

(If you have several gmail account, check if this page is connected to the right account).

In my case it was OFF, I could download the mail, but could not send them.

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