Why Outlook May Route IMAP, POP, and SMTP Through Microsoft Servers
Simple Answer
Some versions of Outlook, especially New Outlook, Outlook mobile app, and some Outlook for Mac setups, may connect your email account through Microsoft Cloud Sync instead of connecting directly to the iCoreHosting mail server.
When this happens, our mail server may see Microsoft server IP addresses instead of your real computer, phone, office, or home internet IP address.
Why This Can Cause Problems
If Outlook routes IMAP, POP, or SMTP through Microsoft servers, it may cause login or sending issues because the connection source changes.
Common problems include:
- The mail server sees Microsoft IP instead of the customer IP.
- Security systems may treat the login as unusual.
- Country or location based protection may block the login.
- SMTP sending may fail even when the email password is correct.
- Mail logs may show Microsoft as the connection source.
Important Note
This issue does not always mean the mailbox password is wrong. It may happen because Outlook is connecting through Microsoft Cloud Sync instead of directly connecting to the iCoreHosting mail server.
How To Avoid This Issue
To avoid routing your email through Microsoft servers, please use an email application that connects directly to the iCoreHosting mail server.
Recommended email applications:
- Classic Outlook for Windows
- Apple Mail on iPhone or Mac
- Samsung Mail on Android
- Thunderbird
- Gmail app with manual IMAP setup
What To Avoid
Please avoid using the following if you want direct IMAP, POP, and SMTP connection:
- New Outlook for Windows
- Outlook mobile app
- Outlook setup that shows Microsoft Cloud Sync
- Automatic setup where Outlook configures the mailbox by itself
Recommended Manual Email Settings
Please set up the email account manually using the following settings.
Incoming IMAP Server: mail.yourdomain.com
IMAP Port: 993 with SSL
Outgoing SMTP Server: mail.yourdomain.com
SMTP Port: 465 with SSL or 587 with STARTTLS
Username: Full email address
Password: Email account password
SMTP Authentication: Enabled
Outgoing Authentication: Use same username and password as incoming mail server
Recommended Fix
If the email account was already added into New Outlook or Outlook mobile app, please remove the account, change the email password from cPanel or DirectAdmin, then add the email account again using manual IMAP and SMTP settings.
How To Check If The Issue Is Fixed
After changing to direct IMAP and SMTP setup, the mail server should see your own internet IP address instead of Microsoft server IP addresses.
If the server log still shows Microsoft IP addresses, the email application is most likely still using Microsoft Cloud Sync.
When To Contact Support
Please contact iCoreHosting support if you have already changed to manual IMAP and SMTP setup but still cannot receive or send email.
When contacting support, please provide:
- Your email address
- The email application you are using
- A screenshot of the incoming and outgoing mail server settings
- The error message shown by your email application
Summary
For best email stability, please use direct IMAP and SMTP setup. Avoid New Outlook or Outlook mobile app if they route your mailbox through Microsoft Cloud Sync. Direct connection allows the iCoreHosting mail server to verify your real login source and reduces unnecessary login or sending issues.
