Google's Advanced Protection Program
Unfortunately, Mimestream cannot log into accounts that have Advanced Protection enabled. We have been in contact with Google about this, but they do not have a process in place to grant Gmail API clients an exception, as the Gmail API has typically been used by server-side applications, rather than native email clients running only on user devices (like Mimestream).
For now, Google’s Advanced Protection Program only allows IMAP-based clients to connect to Gmail. We’d like to eventually support IMAP as a workaround for this issue, so if you’d like to see this supported in Mimestream, please add a +1 to IMAP support on our public roadmap.
Possible Workaround: Workspace Administrator explicitly trusts Mimestream
If you have a Google Workspace account (custom domain) and are the administrator, you have the option of marking Mimestream as trusted to get around this issue:
- Start by visiting https://admin.google.com/ac/owl/list?tab=apps&hl=en
- Click “Configure new app”, choose “OAuth App Name or Client ID”
- Search for “Mimestream”, hover over the result and click Select
- Check off the
googleusercontent.comclient ID and click Select
- Select Trusted, then click Configure
After explicitly marking Mimestream as a trusted app, any user in your domain can log into Mimestream with Google’s Advanced Protection Program enabled for their account.