Gmail Not Sending or Receiving: What's Actually Wrong
Can't even log in? That's a different problem — I covered that separately in our Gmail login post. This one's for once you're already in and something's still not moving right.
The first question I always ask people isn't "what's wrong with Gmail," it's "which half is actually broken" — because sending and receiving fail for genuinely different reasons, and mixing them up wastes a lot of time.
Check gmail.com directly first
Before touching any app, sign in on the website. Broken there too? Account-level issue. Fine there but broken in one app? The fix lives entirely in that app.
When it's sending
Almost always one of three things in my experience: an attachment too large to handle cleanly, a browser extension getting in the way (incognito mode rules this out fast), or — if you're going through a third-party app — an outdated SMTP setting or a missing app password. Gmail needs an app password for third-party clients once 2-Step Verification is on; your normal password just quietly fails there.
When it's receiving
Check the obvious tabs first — Spam, then Promotions and Social. So much "missing" mail is just sitting somewhere you're not looking. After that, an old filter silently archiving or forwarding things is the next most likely thing, and it's genuinely easy to forget one exists months later.
When it's both at once
This usually points to storage. Gmail's quota is shared with Drive and Photos on a personal account, so "email is broken" can quietly mean your Photos library filled up the shared space — nothing to do with your inbox at all.
When it looks fine but feels slow
Worth a quick check of the Google Workspace Status Dashboard before assuming it's your account. Occasionally it really is on Google's end.