Problem guide · 8 fix-it guides · Last reviewed · By Harry
Email not sending, receiving or syncing
Mail not arriving, stuck in the Outbox, going to spam or Outlook disconnected? Split an Exchange Online or Gmail incident from client, rule and DNS faults.
Email tickets arrive as "email is down", but very few of them turn out to be a real mail-platform incident. Most are one of four things: the desktop client is disconnected or corrupt while the mailbox itself is fine; mail is arriving but a rule, Focused Inbox or a spam filter is hiding it; messages are genuinely delayed in a queue; or the sending domain's SPF, DKIM or DMARC records are making other providers distrust it.
The fastest split is web versus desktop. If Outlook on the web or Gmail in a browser shows the message, the service is up and the client is the problem. If the web shows nothing either, look at a message trace (Microsoft 365) or Email Log Search (Google Workspace) before anyone declares an outage.
Which guide fits your symptom?
Mail not arriving or delayed
- Outlook not receiving email or empty Inbox: Exchange or the client?Outlook shows an empty Inbox or no new mail, and you need to know if it is Exchange or the client.
- Gmail not receiving email in Google Workspace: what to checkA Google Workspace mailbox stops receiving mail: spam and filters first, then MX and routing.
- Exchange Online mail delivery delay or messages stuck in queueMail arrives late, sits in the Outbox, or a bounce says it is still being processed.
Mail going to spam
Outlook desktop problems
- Outlook disconnected or not syncing: is it Microsoft or you?Outlook desktop says Disconnected or stops syncing, while webmail may still work.
- Outlook keeps asking for a password: how to stop the promptsOutlook keeps showing password prompts on Microsoft 365.
- Outlook search not working or returning no resultsOutlook search returns nothing, misses recent mail or warns results may be incomplete.
- Shared mailbox not showing in OutlookA shared mailbox is missing from Outlook, not updating, or sent items land in the wrong place.
Also worth a look
These guides live under another problem type but often turn up with this symptom.
- Entra ID / Azure AD password reset email or code not arrivingThe message that never arrives is a password reset email.
- Can't open Teams meetings from OutlookClicking Join in an Outlook meeting invite does nothing.
Related status pages
Live vendor status, checked every five minutes. If the vendor has posted an incident, the guides above become a waiting game rather than a fix.
FAQ
- How can I tell if Outlook or Exchange Online is down?
- Open Outlook on the web for the same mailbox. If it works, Exchange Online is up and the desktop client is the problem. If it fails for many users at once, check the Outlook status page and Service health in the Microsoft 365 admin centre.
- Why are my emails arriving late?
- Usually a queue at the sending side, filtering at the receiving side, or an Outbox that is not sending from the client. A message trace shows the timestamps at each hop, which is the only reliable way to see where the delay happened.
- Why do my emails go to spam for other people?
- Most often missing or misaligned SPF, DKIM or DMARC records for your domain, or a sudden change in sending volume. Fix the DNS authentication first; asking recipients to add you to a safe-senders list only hides the problem.
- Is it safe to rebuild the Outlook profile?
- For Microsoft 365 mailboxes the mail lives on the server, so yes. Create a new profile alongside the old one and leave the old data file alone until the new profile works. Local PST archives are the exception: back those up first.