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:

  1. Start by visiting
  2. Click “Configure new app”, choose “OAuth App Name or Client ID”
  3. Search for “Mimestream”, hover over the result and click Select
  4. Check off the client ID and click Select
  5. 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.