Not Receiving Emails? How to Diagnose and Fix Email Delivery Issues

Few things are more frustrating than missing an important email — or discovering hours later that people have been trying to reach you with no success. When emails aren't coming through, the cause could be anything from a misconfigured DNS record to a full inbox. This guide walks you through every likely culprit, starting with the most common causes first.

Start Here: Check Your MX Records

Before anything else, verify that your domain's MX records are configured correctly. MX records are the DNS entries that tell the internet which mail server should receive email for your domain. If these are wrong or missing, email simply cannot reach you — no matter what else you do.

Head to mxrecordchecker.com and enter your domain name. You should see results within seconds. What you're looking for:

At least one MX record exists
The mail server hostnames match your email provider (Google, Microsoft, Zoho, etc.)
The servers show as responding

If the tool returns no MX records, or shows server hostnames you don't recognize, that's almost certainly why you're not receiving emails. Skip down to the DNS section of this guide and fix that first before investigating anything else.

Why Am I Not Receiving Emails? The Most Common Causes

1. MX Records Are Wrong or Missing

As covered above, this is the first thing to rule out. MX records can go missing because:

You recently moved to a new hosting provider or domain registrar and the DNS wasn't fully transferred
Someone accidentally deleted them while making other DNS changes
Your domain expired and was suspended
You set up a new domain but never configured email

The free MX checker at mxrecordchecker.com shows you exactly what the internet sees for your domain. If the records are wrong, contact your domain registrar or DNS provider to fix them.

2. DNS Propagation Is Still in Progress

If you recently changed your MX records, DNS propagation takes time. Changes you make at your registrar need to spread across DNS servers worldwide, which typically takes 15 minutes to a few hours — though it can take up to 48 hours in rare cases.

During propagation, some mail servers see your old records and some see the new ones. This means email delivery becomes inconsistent. Some senders may reach you fine while others get bounces or delays.

If you've recently changed MX records, wait at least a few hours and then re-check with the MX lookup tool to confirm the new records are visible globally.

3. Spam or Junk Folder

This sounds obvious, but it's easy to overlook. Aggressive spam filters in Gmail, Outlook, and Yahoo frequently misclassify legitimate emails, especially:

Newsletters and marketing emails from small senders
Automated notifications from software tools
Emails from unfamiliar senders or new contacts
Emails with certain subject line patterns or attachments

In Gmail: Check the Spam label in the left sidebar. If you find a legitimate email there, click "Not Spam" to train the filter.

In Outlook: Check the Junk Email folder. Right-click any legitimate email and select "Not Junk" to move it and prevent future filtering.

In Yahoo Mail: Look for a Spam folder in your folder list. Mark legitimate emails as "Not Spam" to improve accuracy over time.

4. Full Inbox or Storage Quota

When your mailbox is full, incoming email bounces back to senders. The sender receives a delivery failure notification, but you receive nothing — and may not even know it's happening.

Gmail gives each Google account 15GB shared across Gmail, Drive, and Photos. Check your storage at one.google.com/storage. If you're near the limit, delete old emails, empty the trash, and clear Drive files.

Microsoft 365 business plans typically provide 50GB per mailbox by default, with expansion options. Your IT administrator can check mailbox size and increase limits.

Yahoo Mail offers 1TB of storage, so this is rarely an issue, but it's worth checking if you've had the account a long time.

5. SPF, DKIM, and DMARC Rejection

If the sender's email authentication is broken, your mail server may reject their messages before they even reach your inbox. You won't see these emails anywhere — they're rejected at the server level.

SPF is a DNS record that specifies which servers are allowed to send email for a domain. If a sender's SPF is broken or missing, your server may reject their mail.
DKIM is a cryptographic signature that proves the email wasn't tampered with in transit. Failed DKIM can trigger rejections.
DMARC is a policy that tells receiving servers what to do when SPF or DKIM fails — reject, quarantine, or allow the email.

If you're specifically not receiving emails from one particular sender, ask them to check their SPF and DKIM records. Tools like spfrecordcheck.com can help them verify.

6. Sender Is Blocked

Someone on your team may have blocked the sender. In Gmail, blocking a sender sends their messages directly to trash. In Outlook, blocked senders go directly to Junk.

In Gmail: Go to Settings > See all settings > Filters and Blocked Addresses. Check whether the sender's address or domain appears in your blocked list.

In Outlook: Go to Home > Junk > Junk Email Options > Blocked Senders. Review the list for any unintentional blocks.

7. Email Forwarding Configuration Issues

If you have email forwarding set up — sending email from one address to another — a misconfigured forward can cause emails to vanish silently. Common issues include:

A forwarding rule that also deletes the original
Forwarding to an address that no longer exists
A filter that catches emails before the forward rule can apply

Review any email forwarding settings in your account or hosting control panel.

8. Server-Side Issues at Your Email Provider

Sometimes the problem is completely outside your control. Email providers experience outages, delays, and routing issues that can cause temporary delivery failures.

Check your email provider's status page:

Google Workspace: workspace.google.com/status
Microsoft 365: status.office365.com
Yahoo Mail: help.yahoo.com/kb/SLN26455.html

If there's a known incident, you'll need to wait for the provider to resolve it.

Diagnosing Gmail Not Receiving Emails

If you're on Gmail and not receiving emails, work through this checklist:

Check the Spam folder
Check that storage isn't full (one.google.com/storage)
Look for filters that might be archiving or deleting emails (Settings > Filters)
Check blocked senders list
If on Google Workspace, run the MX record check at mxrecordchecker.com to verify domain configuration
Review Google's email log search (Workspace admins only) to trace specific messages

Diagnosing Outlook Not Receiving Emails

For Outlook users (including Microsoft 365):

Check the Junk Email folder
Review the Blocked Senders list (Home > Junk > Junk Email Options)
Check for rules that move or delete incoming mail (File > Manage Rules & Alerts)
Verify your mailbox isn't full (File > Info > Mailbox Cleanup)
If on Microsoft 365, use the Message Trace tool in the Exchange admin center to track specific emails
Check your MX records at mxrecordchecker.com if using a custom domain

When to Escalate

If you've worked through all of the above and still can't identify the issue, it's time to involve your IT team or email provider's support. When you contact them, have this information ready:

The sender's email address
Approximate time they tried to send
Any bounce or error messages the sender received
Results from the MX record checker

For ongoing visibility into your email infrastructure, deliverabilitychecker.com monitors your MX records, SPF, DKIM, and DMARC daily and alerts you before problems become critical — so you're not discovering email outages after the fact.