Email Sent but Never Arrived? How to Trace It

Bounce, quarantine or silent drop: what happened to the email

An email can fail in several places between your outbox and the recipient's inbox. Knowing which one tells you who has to fix it.

If you did get a bounce, our email bounce-back errors guide explains the common codes. The rest of this guide covers the harder case: no bounce, no email.

First checks before you open the admin console

• Spelling of the address: look at the exact address in your Sent item, not the contact name. One wrong letter in the domain sends it elsewhere.
• Outbox: in Outlook, a message stuck in the Outbox shows as sent from your point of view only if you look in the wrong folder.
• Attachment size: large attachments may be rejected by the recipient's server. Try again with a sharing link instead.
• Only one recipient or many: if several different companies are not receiving your emails, the problem is likely your domain's SPF, DKIM or DMARC setup, not their spam filter.

If many recipients are affected, start with our guide to emails going to spam and SPF, DKIM and DMARC. If it is one company, keep going.

How to run a message trace in Microsoft 365

Microsoft's message trace documentation says the tool shows whether the service received, rejected, deferred or delivered a message, and what actions were taken on the way. You need an Exchange or Microsoft 365 admin role.

1. 1

   Open the Exchange admin center

   Go to admin.exchange.microsoft.com, then Mail flow, then Message trace.

2. 2

   Start a new trace

   Enter your address as sender and the customer's address as recipient. The default range is the last two days; widen it if needed.

3. 3

   Keep the range under 10 days if you can

   Microsoft says results for 10 days or less appear instantly. Up to 90 days is possible, but older searches are prepared as a downloadable report that can take several hours.

4. 4

   Read the delivery status

   Delivered, Failed, Pending, Quarantined, Filtered as spam, Expanded (sent to a group) or Getting status. Microsoft notes status can lag five to ten minutes.

5. 5

   Open the message details

   The detail view shows each event, such as Receive, Send and Deliver, with the receiving server's response. Copy the message ID from here.

If the trace shows Failed, the detail view gives the reason, and Microsoft's non-delivery report reference explains each code.

How to use Email Log Search in Google Workspace

Google Workspace admins have Email Log Search (ELS) in the Admin console, under Reporting. Google's help says it can find messages sent and received by your users by sender, recipient, date or message ID.

Google's data retention help says Email Log Search keeps Gmail data for 30 days. For older messages, you need the recipient address and message ID, and you only get limited status information. Search early.

Open the result to see the delivery steps. If Gmail handed the message to the recipient's server and got an accepted response, it left Google successfully. If the recipient is also on Google Workspace, ELS can sometimes show more about what happened after delivery inside your own organisation, but not inside theirs.

Delivered but not in the inbox: the recipient's side

If your trace says Delivered, their server accepted the email. From there, their own systems decide where it goes. Common places it ends up:

• Junk or spam folder in Outlook or Gmail.
• Admin quarantine: Microsoft's quarantine documentation says quarantined messages are kept for 15 or 30 days by default depending on the reason, and only their admin may be able to release some of them.
• A third-party email gateway in front of their mailbox, which keeps its own quarantine.
• Inbox rules that move or delete messages, sometimes set up by an attacker on a compromised account.
• Focused or Other tab in Outlook, or a Gmail category tab.
• Shared mailbox or group that nobody watches, if you sent to a generic address.

If the same recipient often misses your emails in Outlook specifically, our guide to emails going to spam in Outlook covers sender reputation and safe-sender lists.

What to send the recipient's IT team

Most IT teams can find a message in minutes if you give them the right details. Send this by phone, WhatsApp or from a different email account, in case your messages are being filtered.

The message ID is the key item. It is unique to that email and appears in both your logs and theirs.

Do it yourself or get help?

If you have admin access, a trace takes a few minutes and settles most disputes about whether an email was sent. It gets harder when several companies miss your emails, or the trace shows your own system filtering outgoing mail, which can point to a compromised account or a domain authentication problem.

For a single message mystery, our Quick Fix (1 hour) (S$119) covers a trace and a clear explanation. If many emails are not arriving or going to spam, our email deliverability fix (S$249) checks and fixes SPF, DKIM, DMARC and sender reputation.