Start by working out which direction is failing. Send a short test message from another email account to your Gmail address, and send one from Gmail to that other account. A message that never leaves Gmail is a sending problem. One that never shows up is a receiving problem. If both fail, the cause is usually storage, the account, or your connection.
Check these first
- Google storage. Gmail, Google Drive, and Google Photos share one storage allowance, and when it's full Gmail can stop accepting new mail. Check it at one.google.com/storage, then delete large files and empty Spam and Trash to free space. For a detailed cleanup walkthrough, see how to free up Google Drive storage safely.
- Gmail in a browser. Open mail.google.com. If Gmail works there but not in the app, the problem is the app or your phone's sync settings. If Gmail fails only in one browser, try a private window or another browser first; if that works, clear the affected browser’s cache and cookies.
- Service status. Check google.com/appsstatus. If Gmail is listed as having an outage, wait and try again later.
- Connection. Load another website to confirm you're online. Try Wi-Fi if you're on mobile data, or the reverse.
If mail isn't arriving
- Search all your mail. Search for the sender or subject, and check Spam, Trash, and All Mail. The message may have been archived or filtered rather than lost.
- Review your filters. On the web, click the gear icon, choose See all settings, then open Filters and Blocked Addresses. Look for filters that delete messages or skip the Inbox, and remove any you don't recognize. On the same tab, check the blocked list, because mail from blocked senders goes to Spam. Also review forwarding rules; if automatic forwarding is the problem, see this guide to fix email forwarding issues.
- Check forwarding and POP/IMAP. Under See all settings > Forwarding and POP/IMAP, make sure mail isn't being forwarded somewhere you didn't intend. If another mail app downloads your mail by POP, check what the setting does with Gmail's copy after download.
- Ask the sender for the bounce message. If their message was rejected, the error text explains why. An address typo is a common reason.
If mail isn't sending
- Check for a stuck message. On the web you may see "Sending…" for a while, and in the app a message can sit in the Outbox. Open it and look for an attachment problem. Gmail's attachment limit is 25 MB, and larger files are added as Google Drive links, which needs working Drive storage and sharing.
- Read the bounce message. A failed message returns a notice from Mail Delivery Subsystem. It names the reason, such as an address that wasn't found, a blocked message, or a full mailbox on the recipient's side. See how to interpret email bounce messages for more help.
- Retry from the web. Copy the text into a new message in a browser and send it. If that works, the problem is limited to the app.
- Slow down bulk sending. If you've sent many messages recently, Gmail may temporarily limit sending. Wait a day before trying again.
If it only fails in the Gmail app
- Update the Gmail app and your phone's operating system.
- Make sure Gmail sync is on. In the app's settings for your account, check that Sync Gmail is turned on, and confirm the same in your phone's account settings. Menu names vary by device and version.
- Restart the phone. On Android, you can also clear the Gmail app's cache under Settings > Apps > Gmail > Storage.
- As a last step, remove the Google account from the phone and add it again. Your mail is stored on Google's servers, so it will download again.
If you use Gmail in another mail app
Use the app's Sign in with Google option where it exists. An app that only offers a plain password login may be outdated, and updating it or switching to a current app often fixes sign-in errors. Never turn off 2-Step Verification just to get an app to connect.
Check for account security problems
Unfamiliar filters or forwarding rules can mean someone else has had access to your account. They may hide or redirect mail on purpose. If you find rules you didn't create:
- Delete them.
- Open your Google Account's Security page and review recent activity and signed-in devices.
- Change your password and make sure 2-Step Verification is on.
When to contact Google or your administrator
- Gmail shows a message that the account is suspended, restricted, or needs verification.
- Storage is fine, no filters interfere, and mail still fails in a browser on another network.
- It's a work or school account. Your administrator controls many of the settings and may need to check the domain's mail setup.
If a particular recipient never receives your mail, ask them to check Spam and any filters on their side. A rejected message returns an error you can use to diagnose the problem.
What to do next
Most Gmail delivery problems come down to full storage, a filter or forwarding rule, or an app that has stopped syncing. Check those in order, keep any error text you see, and contact support only when the web version fails too.