Summary

After connecting a Google custom mail handler using the OAuth method, no incoming messages are processed.

Error in the connectivity logs

The mail handler connection logs return the following errors:

com.google.api.client.googleapis.json.GoogleJsonResponseException: 403 Forbidden GET https://gmail.googleapis.com/gmail/v1/users/xxxxxxxxxx/messages?maxResults=300&q=in:inbox%20label:unread%20after:xxxxxxxxx { "code" : 403, "details" : ...

Retrying in XX minutes - Email pulling has failed X times consecutively (Reason: com.google.api.client.googleapis.json.GoogleJsonResponseException: 403 Forbidden GET https://gmail.googleapis.com/gmail/v1/users/xxxxxxx/messages?maxResults=3...

Give Google the necessary permissions to read the emails

This usually means that Jira wasn't granted access to read the messages in Google Inbox.

To make sure the email will be connected and Jira can read the emails, it's advised to reconnect the email account and make sure that the last OAuth permissions scope checkbox is selected.