Verify your Backup Mail and Mail Server Forwarding Services

Even though we routinely test all of our services from multiple networks around the world we understand that many users often want to verify that their mail is functioning as designed. We have developed this page to assist those that want to "prove" / "check" that their DNS Made Easy services are working as promised.

There are two sections to this article:

1. The actual email tests.
2. Debugging any possible errors you are getting during your tests.

'Email Tests

Please follow these steps to test your Enterprise Backup Email Services or Mail Server Forwarding from DNS Made Easy.

• Make sure that you have given 2 hours to make sure that all of the mail servers have been updated to accept mail with your new configurations. We run mail servers in multiple geographic locations so it does take a little while to update all of the mail clusters securely.
• Some possible tests are:
  • 1) Turn off your mail server temporarily and send yourself an email. Most users do not want to do this or will only do this late at night. This will only work of course if you already changed your MX records.
    
    or
    
  • 2) Change the settings in your mail client (such as Outlook) to use the DNS Made Easy mail servers as your SMTP server. Then send yourself an email. The backup mail server will relay the email to the final destination.
    
    or
    
    
  • 3) If you understand the SMTP protocol you can telnet to the DNS Made Easy mail servers (on port 25) and send yourself an email message.

    In this example we will send email to a user "sales@example.com" and send it from "support@example.com". The items in bold are the ones that you would type. You will also want to use the mail servers that were assigned to you. In this example we will just use "mx1.dnsmadeeasy.com" for testing purposes.

    # telnet mx1.dnsmadeeasy.com 25
    Trying 205.234.170.136...
    Connected to mx1.dnsmadeeasy.com.
    Escape character is '^]'.
    220 mx1.dnsmadeeasy.com ESMTP TiggeeSMTP (1.0.1)
    ehlo mx3.dnsmadeeasy.com
    250-mx1.dnsmadeeasy.com
    250-PIPELINING
    250-SIZE 20240000
    250-VRFY
    250-ETRN
    250 8BITMIME
    mail from: <supportstaff@example.com>
    250 Ok
    rcpt to: <sales@example.com>
    250 Ok
    data
    354 End data with <CR><LF>.<CR><LF>
    This is a sample email.
    .
    250 Ok: queued as 783C7B9E0A8
    quit
    221 Bye
    Connection closed by foreign host.

     

  Debugging possible errors while testing the Backup Email Services.

• Reverse DNS
  • DNS Made Easy makes sure that the connecting system has reverse DNS setup. Most major ISPs also do this check as most spammers run their machines on networks that do not have this.
  • Possible error would be:
    450 Client host rejected: cannot find your hostname , [your IP]
• Domain Sender
  • The sending domain (usually the domain in the from address) must be a valid domain name and it must resolve or have a DNS configuration to allow a bounce.
  • Possible error would be:
    450 <the from email address >: Sender address rejected: Domain not found
• FQDN in helo
  • The system name stated in the helo / ehlo must be a fully qualified domain name. In some of systems this name must also be resolvable. This means that the system must identify itself with a name that is resolvable on the Internet.
  • Possible errors would be:
    504 <hostname>: Helo command rejected: need fully-qualified hostname
    450 <hostname>: Helo command rejected: Host not found
    
    
• RBLs
  • DNS Made Easy does use the following RBLs for your convenience
    • Spamhaus
    • Our own custom RBL that we use to list servers that send thousands of spam / UCE/ UBE emails to us in under a 24 hour timeframe.
• Greylisting - This service is not on the mail server forwarding servers. It is just found on the backup email servers at this time.
  • DNS Made Easy does use Greylisting on all of our backup email servers to prevent most spam from being routed through our networks. This stops post spammers that use the backup email service as a spam relay into your network.
  • Possible error:
    450 <recipient email>: Recipient address rejected: Policy Rejection: Please try later. Greylisting http//www.dnsmadeeasy.com/s0306/res/greylisting.html

If you used these techniques to verify that your domain is working and if you feel that there is problems please open a support ticket.