Authentication Issue

Update:

I tried using the Post STMP Plugin on the 3rd site using the same credentials and it worked. That tells me it’s not a Google API issue. So I’m thinking that your plugin must not be using newly saved credentials even after electing to delete data after deleting the plugin. As a test, I removed the Post SMTP plugin then tried to re-installed WP Mail SMTP and had the same authentication problem. Once more, I deleted your plugin, reinstalled the Post SMTP plugin using the same credentials and it works. I prefer using your plugin so if you have any ideas, let me know.

Also, I’ve never seen an answer to these questions so perhaps you can answer them…

The email address we that shows up by default in your plugin when going to your Plugin Settings for the first time, it displays the email address used in WordPress/Settings (site admin email address).

1) Is it possible to use another Gmail or G Suite email address other that what’s used in WordPress Settings?

2) If yes, does that email address need to be a user within that WordPress install?

3) If yes, does that other email address you want to use need to have Administrative Privileges?

4) If the password for the email address you use changes, does stop your plugin from working? If yes, do you simply need to re-Authorize within your plugin?

5) Why does your plugin prevent us from changing the From email address after saving and authorizing?

Hi @webauthor,

The highest PHP version I tested with was 7.4.7:
Server architecture. Linux 4.19.76-linuxkit x86_64
Web server Apache/2.4.38 (Debian)
PHP version 7.4.7 (Supports 64bit values)

And the Gmail connection was successful.

The error that you got:

> There was an error while processing the authentication request. Please try again.

Was it exactly like this or did it have an additional error description next to it?

If it’s without additional error description, it means that the authorization code or the scopes passed back to your WP site after the Google authorization were incorrect. Either authorization code: code URL parameter is empty or the scopes returned do not match a combination of “https://mail.google.com/” and “https://www.googleapis.com/auth/gmail.send”.

Without debugging your specific case I don’t know what the actual issue is.

> Do you know if there is a limit on the the number of times you can authorize an app using the same app and but different credentials using the same email address?

Yes, the limit for connections with same oAuth2 credentials is around 25. Are you reaching this limit? If you have these 3 sites and this Google account is not used in other ~22 sites/apps (not just our plugin, but whatever Google account oAuth connection), then it should be OK.

> Lastly, is it necessary to fully delete the plugin and data when changing the Client Keys? If so, you may want to consider offering a way to flush the data from the plugin instead of having to delete then re-install.

If you don’t have any hard DB caching, then it should not cause issues and just changing the client Id and secret (+ saving the settings) should suffice.

Answers to your second post:
1) yes, once you are authorized with Gmail mailer, you will be able to select the “From Email” form all your registered Gmail “Send as email” (aliases).

2) No, the “From Email” will always be the authorized Gmail/G-suite address or its aliases.

3) No, look at the #2 answer.

4) Yes, if you change the authorized Google account’s password it may break the functionality and you would have to remove the connection and re-connect it in the plugin settings.

5) Because in order for the Gmail API to work properly, it has to send the emails as the authorized Google account email address (or its aliases).

Take care!