550 <user@domain.com> No such user here

Issue:

You are able to send emails successfully via the webmail interface, but encounter bounce-back errors when sending emails through a desktop email client such as Microsoft Outlook. The error message typically reads:

 

The following recipient(s) could not be reached:
user@domain.com on [date and time]
550 user@domain.com: No such user here

 

Cause:

This issue is typically due to incorrect email client configuration.

 

Resolution:

Please follow the steps below to resolve the problem:

 

1. SMTP Server Configuration

   Ensure that your outgoing (SMTP) mail server is set to:

   mail.yourdomain.com

   (Replace yourdomain.com with your actual domain name hosted on our servers.)

2. From Address Validation

   Set your “From” email address to the same as your email login address.

   For example, if your email login is user@yourdomain.com, your “From” address must also be user@yourdomain.com.

   The server enforces this to prevent spoofing and unauthorized use.

3. Enable SMTP Authentication (for Outlook users)

   If you’re using Microsoft Outlook (e.g., Outlook 2003 or newer), do the following:

    

   • Go to Account Settings

   • Click More Settings

   • Select the Outgoing Server tab

   • Check the box: My outgoing (SMTP) server requires authentication

   • Ensure Use same settings as my incoming mail server is selected

    

 

 

Once these settings are updated, restart your email client and try sending the email again. This should resolve the bounce-back issue.