imap-mail.outlook.com is Not Responding: What It Means and How to Solve It

If you’re seeing the error “imap-mail.outlook.com is not responding,” it means your Outlook app can’t connect to Microsoft’s mail server. This issue can stop you from sending or receiving emails on a desktop or a mobile. Recently, I’ve faced this problem, and luckily, I found some tricks to resolve this error.

Through this guide, I’ll explain what causes it and how to fix it step-by-step to restore the Outlook connection quickly. So, let me first explain what this error is. 

Table of Contents

• What Does it Mean?
• What Are the Causes Behind This Issue?
• How I Fixed it Step by Step
• Additional Tips
• Backup IMAP Data When Outlook Isn’t Responding
• When to Contact Microsoft Support?
• Author’s Verdict
• People Also Ask

What Does imap-mail.outlook.com Is Not Responding Mean?

Before learning the troubleshooting steps, let’s first understand what this error means, which helps you to prevent this in future. 

So, when you use Outlook with an IMAP configuration, your email client connects to Microsoft’s Outlook mail server (imap-mail.outlook.com) to sync emails across all your devices. If this server isn’t responding, it means your device is unable to establish or maintain a stable connection to the Outlook IMAP server.  

You see this error message on:

• Outlook desktop app
• iPhone/iPad Mail app
• Android email clients
• Third-party apps like Thunderbird or Apple Mail

The message varies slightly, like:

• Cannot connect to the mail server
• Connection to the server failed
• IMAP server not responding

Whatever the error message prompts, the problem is the same: a communication failure between your device and Outlook’s mail server. But do you know why this occurs? If not, don’t worry, I’ll explain it next.

What Are the Causes Behind This Issue?

To fix imap-mail.outlook.com is not responding permanently, it is mandatory to know all the key factors that lead to this issue:

1. Internet connectivity issues
2. IMAP authentication failed or incorrect IMAP/SMTP settings
3. Outdated Outlook or iOS/Android version
4. Corrupted Outlook profile or cache
5. Firewall or antivirus interference
6. Server outage on Microsoft’s end
7. Two-step verification or app password issues

After reading these, I’m sure one thing is clear that all these factors are fixable. Trust me, in the next sections, I’ll explain how you can resolve the imap-mail.outlook.com issue permanently.

How I Fixed the imap-mail.outlook.com Is Not Responding Error Step by Step

Below are the solutions to all the causes we discussed earlier, and it is recommended not to skip any step. However, if your issue is resolved by following only the first two steps, then skip the rest. Let’s go through each fix one by one, i.e.

#Step 1. Check Internet Connection

Whenever I faced this issue, I first checked the internet connection, which is the major cause which leads this issue. For the same, try these quick steps:

• Open a browser and load any website.
• Switch from Wi-Fi to mobile data or vice versa.
• Restart the router if the network is unstable.

If websites load fine but Outlook still can’t connect, move to the next step.

#Step 2. Verify IMAP Settings in Outlook

Incorrect IMAP configuration is the most common cause behind this: imap-mail.outlook.com is not responding. So, always double-check the settings against Microsoft’s official configuration:

Incoming Mail (IMAP):

• Server: imap-mail.outlook.com
• Port: 993
• Encryption: SSL/TLS

Outgoing Mail (SMTP):

• Server: smtp-mail.outlook.com
• Port: 587
• Encryption: STARTTLS

Make sure “My Outgoing server (SMTP) requires authentication” is checked, and use the same username and password as the incoming server.

If any of these values are incorrect, correct them and restart Outlook.

#Step 3. Remove and Re-add the Outlook Account

When settings are correct but the imap-mail.outlook.com is not responding, persists, then trying to remove and re-add the email account fixes corrupted sync configurations. I think this is the easiest task. Still, I’ll provide you with the steps below to do so:

In Outlook Desktop:

1. Go to File > Account Settings > Account Settings.
2. Select the Outlook account and click Remove.
3. Click Add Account and re-enter the credentials.

On iPhone/iPad:

1. Go to Settings.
2. Then, hit the Mail option.
3. Afterwards, select the Accounts > Outlook.
4. Tap Delete Account, then add it again.

This refreshes the connection between Outlook and the IMAP server. Most probably, the issue will be resolved.

Related article: Archive IMAP Emails

#Step 4. Disable Firewall or Antivirus Temporarily

Sometimes, an antivirus or firewall blocks the IMAP or SMTP ports. To check this:

• Temporarily disable the antivirus or firewall.
• Try reconnecting the Outlook account.

If the service runs perfectly, then whitelist Outlook in the antivirus settings to prevent future blocking.

#Step 5. Check for Outlook or OS Updates

Outdated software can conflict with modern SSL/TLS protocols. So:

For Outlook Desktop:

• Go to File.
• Then click on the Office Account.
• Now, select the Update Options > Update Now.

For iPhone/iPad:

• Open Settings.
• Afterwards, click General > Software Update.

For Android:

• Open the Play Store.
• Go to the Manage Apps option. 
• Now, press the Outlook > Update.

#Step 6. Generate an App Password, If MFA Is Enabled

If you’ve enabled multi-factor authentication (MFA) in the Microsoft account, Outlook or older email clients will reject your normal password and leading to imap-mail.outlook.com is not responding. In that case:

1. Log in to the Microsoft account.
2. Go to Security > Advanced Security Options.
3. Under App passwords, click Create a new app password.
4. Use that password when signing in from your email app.

#Step 7. Repair or Rebuild Outlook Data Files

Sometimes the problem is in corrupted .ost or .pst files. Fortunately, Outlook has a built-in repair tool for this. For the same:

1. Exit Outlook.
2. Open Control Panel > Mail > Data Files > Open File Location.
3. Locate the .pst file.
4. Run SCANPST.EXE (Inbox Repair Tool).
5. Select the file and click Start to repair it.

Once the repair completes, restart Outlook and test the connection again.

#Step 8. Check Microsoft Service Status

If all else fails in resolving the imap-mail.outlook.com is not responding error, visit Microsoft 365 Service Status to check if Outlook servers are experiencing downtime.

If found, the issue is on Microsoft’s end; you’ll need to wait to fix it.

Additional Tips

• Clear Outlook Cache:
  Close Outlook > Press Windows + R > Type %localappdata%\Microsoft\Outlook > Delete .ost files.
• Reinstall Outlook App:
  A clean install sometimes resolves configuration corruption.
• Use Outlook Web App (OWA):
  Access your mail at outlook.office.com until the desktop or mobile issue is resolved.

Backup IMAP Data When Outlook Isn’t Responding

If you keep seeing the “imap-mail.outlook.com is not responding” error and still can’t access your mailbox after trying all the fixes, don’t panic. 

In such cases, I recommend using the SysTools IMAP Backup Software. It lets you securely back up all your IMAP mailbox data to your local system, including emails, attachments, folders, and more.

With this tool, you can:

• Back up IMAP mailbox data to formats like PST, EML, MBOX, MSG or PDF.
• Access your backed-up emails offline without Outlook.
• Protect mailbox data from accidental loss or sync issues.
• Supports incremental and specific date range backups for regular protection.

Once you have a local backup, you can easily open your emails anytime, even if Outlook isn’t working or the IMAP server is down. For the same, you can try this for free.

When to Contact Microsoft Support?

If none of these methods fixes your issue, your account may have server-specific problems or temporary lockouts. I recommend contacting Microsoft Support via the official Outlook Help Center.

They can check your account logs and help reset server configurations on their end. Your issue will be fixed quickly.

Author’s Verdict

As per our discussion, I hope one thing is clear that imap-mail.outlook.com is not responding error always occurs due to:

• Wrong settings
• Authentication issues
• Temporary service downtime

By following the steps above, one can resolve this problem without needing any technicalities or coding. Resolving this is easy and hassle-free with this guide, so bookmark this for future use.

People Also Ask

Q. What is IMAP in Outlook?
IMAP (Internet Message Access Protocol) allows Outlook to sync emails across multiple devices. This means one can access their email data from any location, as it keeps it stored on the mail server.

Q. Is IMAP-mail.outlook.com secure?
Yes, it uses SSL/TLS encryption for secure communication between your device and Microsoft’s mail servers.

Q. Can I use POP instead of IMAP?
You can, but POP downloads emails locally and doesn’t sync them across devices.

Q. Why does this error occur frequently on iPhones?
It often happens after iOS updates or when authentication tokens expire. Removing and re-adding the account quickly fixes it.