Email tends to fail at the worst moment. A client says your proposal never arrived, or your inbox simply stops updating. And “email not working” can mean a dozen different problems, not all of them on your computer.
Even the biggest platforms have rough patches. According to Microsoft’s published service data, worldwide Microsoft 365 uptime was 99.526% in Q1 2026, compared with 99.994% in Q2. That dip is a reminder that some email problems start on the provider’s side, where no amount of restarting your laptop will help.
Below, we break down why email stops sending, receiving, or loading, and what to do about each problem.
First, Identify What Kind of Email Problem You Have
Matching your symptom to the right area saves wasted troubleshooting.
| What’s Happening | Likely Area | Quick Check |
|---|---|---|
| Can’t open email or sign in | Password, account, or MFA | Sign in through webmail in a browser |
| Emails not arriving | Filters, inbox rules, storage, or sender issues | Check Junk, quarantine, and inbox rules |
| Emails not sending | Connection, Outbox, attachment size, or authentication | Look for stuck messages in the Outbox |
| Bounce-back messages | Wrong address, full mailbox, or blocked domain | Read the error code in the bounce |
| Everyone at the company affected | Provider outage, domain, or DNS | Check the provider’s status page |
One of the fastest tests is opening your email in a web browser. If webmail works but Outlook or your phone app doesn’t, the problem is the app or device, not your account.
The Most Common Reasons Email Stops Working
1. A Service Outage at Your Email Provider
When email stops for everyone, check the provider first. Microsoft 365 administrators can see active incidents under Service health in the Microsoft 365 admin center, and Google Workspace publishes a public status dashboard.
During an outage, avoid resetting accounts or reinstalling apps, which can create new problems once service returns.
2. Internet or Network Connection Problems
If websites also load slowly, the issue is connectivity rather than email. Our guide on what causes random internet slowdowns at work can help you narrow it down.
3. Password, Sign-In, or MFA Issues
An expired password, a password change your phone hasn’t picked up, or a missed multi-factor authentication prompt can make email quietly stop syncing.
If you didn’t change your password and suddenly can’t sign in, treat it as a possible security issue, not just an annoyance.
4. A Full Mailbox
Once a mailbox hits its storage limit, new messages may stop arriving and senders get bounce-backs. Emptying Deleted Items and archiving large attachments usually fixes it.
5. Emails Landing in Junk, Spam, or Quarantine
Many “missing” emails were delivered, just not to the inbox. Check Junk, quarantine, and inbox rules, which can move or delete messages automatically.
A rule you didn’t create, especially one that forwards or deletes messages, can mean someone else has access to your account.
6. Outlook or Mobile App Problems
If webmail works fine, focus on the app. Common fixes include:
- Make sure Outlook isn’t set to Work Offline
- Close and reopen the app, or restart the device
- Install pending app and system updates
- Remove and re-add the account on your phone
A corrupted Outlook profile can also cause sync problems, and rebuilding one is best left to IT.
7. Domain and DNS Problems (Business Email)
This common hidden cause often shows up as messages to customers landing in spam or bouncing. Business email depends on DNS records that route mail and prove it’s legitimate:
- MX records tell other servers where to deliver mail for your domain.
- SPF lists the servers allowed to send mail on your domain’s behalf.
- DKIM adds a digital signature to outgoing messages.
- DMARC tells receiving servers how to handle mail that fails those checks.
Major mailbox providers, including Gmail and Yahoo, have tightened sender authentication requirements in recent years, and those rules continue to evolve. A missing or broken record can make mail that used to go through suddenly start failing. An expired domain registration will stop email entirely, which is why renewals should never depend on one person’s memory.
What to Do If Your Email Is Not Working
- Test webmail in a browser to separate account problems from app problems.
- Check your provider’s status page, or ask whether coworkers are affected.
- Confirm your internet connection works for other sites.
- Look in Junk, quarantine, and inbox rules for missing messages.
- Check mailbox storage and clear out large, old items.
- Read any bounce-back message and note the error code.
- Contact IT if the problem affects multiple people, involves repeated bounces, or looks like unauthorized access.
When It’s Time to Call IT Support
Some email problems are temporary, but recurring or widespread issues can point to something that needs a closer look.
Consider reaching out for help when:
- Emails keep failing to send or arrive
- The same problem keeps coming back
- Multiple employees are affected
- You suspect an account or security issue
- Email is not working across multiple devices
- A business-critical email issue is causing downtime
For businesses, email problems can quickly get in the way of everyday work. Our IT support team helps identify the cause, get your email working again, and reduce the disruption to your team.
Conclusion: Keep Email Working Before It Breaks
Most email problems come down to outages, connectivity, sign-in trouble, full mailboxes, filtering, app glitches, or domain configuration. Testing webmail and reading bounce messages usually points to the right one quickly.
If your team keeps running into the same email issues, the underlying setup may need attention. Contact us to get recurring email problems addressed and keep your business communication running smoothly.
Frequently Asked Questions
1. Why am I not receiving emails but can still send them?
Check your Junk folder, inbox rules, and mailbox storage first. If none of those explain it, your domain’s MX records or a filtering setting may be routing incoming mail incorrectly, which IT should review.
2. Why is my business email going to spam?
Missing or misconfigured SPF, DKIM, or DMARC records are common causes. Sending from a domain with a poor reputation or using spam-like content can also push messages into recipients’ spam folders.
3. How do I know if Outlook or Microsoft 365 is down?
Ask coworkers whether they’re affected and try signing in through a browser. Microsoft 365 admins can confirm active incidents under Service health in the admin center.
4. Why did my email suddenly stop working on my phone?
A recent password change, an MFA requirement, or an app update often breaks mobile email. Removing and re-adding the account usually fixes it once your credentials are current.
5. Can a hacked email account cause email problems?
Yes. Attackers often create hidden rules, send spam that gets your account blocked, or change settings. Unfamiliar rules, sent messages you didn’t write, or unexpected sign-in alerts should be reported to IT right away.
