Helo command rejected: need fully-qualified hostname when sending emails
Wednesday, June 30, 2010 4:20:08 PM (GMT Daylight Time, UTC+01:00)
Simple tip this afternoon. You may have got the following error when sending emails through ASP.Net’s built in mail server before:
From: postmaster@YourWebserversName [mailto:postmaster@YourWebserversName]
Sent: 25 June 2010 13:22
To: sender@sendingdomainname.com
Subject: Delivery Status Notification (Failure)
This is an automatically generated Delivery Status Notification.
Delivery to the following recipients failed.
recipient@recievingdomainname.com
Reporting-MTA: dns;YourWebserversName
Received-From-MTA: dns;YourWebserversName
Arrival-Date: Fri, 25 Jun 2010 13:21:30 +0100
Final-Recipient: rfc822;recipient@recievingdomainname.com
Action: failed
Status: 5.5.0
Diagnostic-Code: smtp;504 <YourWebserversName>: Helo command rejected: need fully-qualified hostname
The fix is easy:
- Open IIS
- View the properties of you Default SMTP Virtual Server
- Go to the “Delivery” tab
- Click the “Advanced” button (in the bottom right corner)
- Under “Fully-qualified domain name” enter a domain name that points to the server
- Click Ok until you’re back to IIS