How to setup MultiPOP for use with Google using OAuth

Google announced that it will begin blocking less secure authentication (LSA) methods. This includes MDaemon's original authentication method used for MultiPOP. MDaemon 23.0.0 supports OAuth for continued use MultiPOP for Google accounts.

HTTPS for MDaemon Webmail must be enabled with a valid certificate. Self-signed certificates are not recommended.

Go to the Google API console: https://console.developers.google.com/
Create a new project
Click OAuth consent screen
Select External
Click Create
Enter an App name, User support email address, and Developer contact address
Click Save and Continue
Click Add or remove scopes
Under Manually add scopes enter https://mail.google.com/
Click Add to Table
Click Update
Click Save and Continue
Click Add users under Test users
Enter the user(s)
In most cases, this should be the google address.
Click Add
Click Save and Continue
Click Back to Dashboard
Select Credentials
Click + Create Credentials
Select OAuth client ID
Select Web application for Application type.
Enter Name
Enter the following in the Authorized redirect URIs section:
https://mail.company.test/WorldClient.dll?View=OAuth&AuthRequest=GMail
NOTE - Change mail.company.test to the FQDN of the MDaemon server
Click Create
Copy the Client ID and Client Secret to a secure location.

In MDaemon:

To create a new MultiPOP profile for a user:

Open MDaemon
Select Accounts
Select Edit Account
Double click on the account to open the account in the Account Editor.
Select MultiPOP
Select Enable MultiPOP
Enter pop.gmail.com:995 for the Server text box.
Enter the Gmail address in the Logon text box.
Enter the Gmail address password in the Password text box.
Verify Enable this entry is checked.
Check the Leave a copy of message on POP server if desired.
Select Use OAuth
Choose the number of days to delete messages older than. (0 = never delete)
Choose the maximum size of messages that MDaemon should download. (0 = no limit)

For existing MultiPOP profiles, administrators will need to enable OAuth for each MultiPOP profile.

Alternatively, the MultiPOP profile can be created or edited in MDaemon's Remote Administration:

Login to Remote Administration as a global or domain admin.
Select Account Manager
Double click the account to edit.
Select MultiPOP from the Account Settings
Double Click on the host or select the host and click Edit to edit an existing profile or click New to create a new MutliPOP profile.
Check the Use OAuth checkbox.
Click Save and Close

End Users must have ...edit MultiPOP settings enabled in order to authorize the account with Google.

Once enabled, the end user will need to perform the steps below to authorize MDaemon to connect to the Google account.