Troubleshooting & FAQ
"This app is blocked" error on Google sign-in
The Gmail API uses OAuth verification, limited to 100 test users. If you're beyond user 100, you'll see this error. Solutions:
- Run from source with your own Google Cloud project credentials.
- Use Outlook — no such quota limit.
- Use IMAP/SMTP — works with any provider.
Google sign-in says "No Google account found"
Ensure you have a Google account added on your device: Settings → Accounts → Add account → Google. Then restart MonoMail.
Microsoft sign-in fails
- Ensure you have a Microsoft account.
- The MSAL configuration uses browser-based auth (not Microsoft Authenticator). Make sure you have a web browser installed.
- Try restarting the sign-in flow.
Notifications aren't working
- Check that Email Notifications is enabled in Settings → Notifications.
- Check that POST_NOTIFICATIONS permission is granted (Android 13+).
- If using the GitHub build, push is disabled — notifications rely on periodic polling (15 min minimum).
- Check the Sync Frequency setting — if set to "Manual", no background polling occurs.
Can't connect to IMAP/SMTP server
- Verify your server addresses (host, port).
- Check SSL/TLS settings:
- IMAP: usually port 993 with SSL, or 143 with STARTTLS
- SMTP: usually port 465 with SSL, or 587 with STARTTLS
- Run the connection test before saving.
- If using a Gmail/Outlook preset, the settings are pre-filled — but you'll need an app password for Gmail if 2FA is enabled.
Where are my scheduled messages?
Tap the calendar badge in the inbox search bar. This opens the Scheduled Messages screen showing all pending sends.
Why is the GitHub build different from the Play Store build?
The GitHub build excludes the developer's Google OAuth credentials for security. It also has push notifications disabled (no FCM on open-source distribution). Outlook/IMAP work identically in both builds.
App feels slow on older devices?
- Disable Smart Grouping in Settings → Inbox
- Reduce animation complexity by using fewer dock tabs
- Consider using fewer accounts (see performance warning when adding 4th+)