Doesn’t Work With GMail

Hi @seancasey,

I’m sorry to hear that your site is experiencing this issue with the Gmail mailer.

Usually when we see the Gmail mailer repeatedly disconnecting from WP Mail SMTP and displaying the ‘invalid grant’ error, it means that your Google API app (OAuth screen section screenshot) is in the “Test mode” and needs to be changed to “Production” to resolve this issue.

Can you please look into adjusting this setting in Google’s API & Services > OAuth consent screen > Publishing status area and see if it resolves this issue for you?

– Other Causes for Gmail Disconnections

The OAuth token in Gmail will reset for any event breaking the connection, including but not limited to:

1. Changing Google password
2. Enabling or disabling 2FA
3. Google account access reset
4. Activation of Google advanced protection program
5. Revocation of the app to profile
6. App OAuth permission revoked by Google
7. App moved from public mode to private/internal mode by Google (or by a user whose user domain is not in the allowed org domain zone)
8. App verification failure on reaudit
9. Suspension of Google account
10. User requested linked account unlinking
11. The user does not use the app for 6 months (automatically expires refresh token)
12. The user adds/removes sensitive or needs review scopes to the app but does not complete the app review process
13. If the user is at the maximum limit for OAuth tokens to a Google profile (50) or for the service (25 for example in analytics), activation of a new refresh key will also automatically revoke the earliest key

To resolve the issue in these instances, please head over to the WP Mail SMTP > Settings page, and click on the “Remove Connection” button. Then click on the “Allow plugin to send emails using your Google account” button to re-enable access.

I know that this issue can be very frustrating to deal with, and I’m sorry again that you’re experiencing it, but I do hope this helps.

Thank you!

We have it in Production Mode and none of the situations you refer to is occuring. Yet, every single day, it disconnects and we need to remove connection and allow again. EVERY SINGLE DAY!! What’s worse is that clients send emails that fail to arrive and they do not know they fail to arrive and we have no idea who attempted to send an e-mail. You would think the plugin would notify the sender that the e-mail failed to send. I urgently need your help with this. This plugin should work easily with a Gmail account, but it has been a nightmare.