Tuesday, November 17, 2015

Exchange Server Error 550 Unable To Relay

User faces problem in sending email with someone’s account and gets the error 550. The error 550 means unable to relay emails or can’t send the email to the recipient.

Error 550 is related to SMTP which occurs while using MS Outlook or an email client with Exchange Server. There are many SMTP errors in which 550 5.7.1 ‘Unable to Relay’ error code 5.0.0, 5.7.1, or 5.7.3 etc. 501 5.7.1 is common.

This article is the continuation of the previous article "Know about the Occurrence of Exchange Server Errors 550,551,552,553,554".

Cause for the Error 550 

  • Error 550 occurs when the email is not delivered to the sender.
  • It happens if the recipient doesn’t support relay, means the receiver domain is restricting the server.
  • Authentication issues occur while establishing connection with the server.
  • Mail server cannot recognize the sender.


Solution involves various methods and different versions of Exchange Server.

For Outlook 2003

1.First Open OutlookExpress2003.
2.Then Go to Tools - Email Account - change email & double click your mail account.
3.Click More Settings - Select Outgoing Server tab and Check the check box My Outgoing Server SMTP Requires authentication.
4.Select Logon on using and give your user ID and Password.
5.Click Ok and Next and Finish.

Verify the SMTP Server

1.Click Start, point to Programs, point to Microsoft Exchange, and then click System Manager.
2.In Exchange System Manager, expand the following object:
Servers\<var>Your_Exchange_Server_Name</var> \Protocols\SMTP
3.Right-click the virtual SMTP server where you want to prevent mail relay, and then click Properties.
4.Click the Access tab, and then click Relay.
5.By default, open relay is blocked. The default settings are as follows:
    a)The Only list below check box is selected.
    b) Allow all computers, which successfully authenticate to relay, regardless of the list above check box is selected.
6.If you must permit a single computer, a group of computers, or a domain to relay through the server, click Add. In the Computer dialog box, click the appropriate selection for the computers you want to relay through the server. Then, type the required information.
7.In the Relay Restrictions dialog box, click OK.
8.Click Apply, and then click OK in the Default SMTP Virtual Server Properties dialog box.

For Exchange Server 2003

1. Open the Exchange System Manager.
2. Go in Administrative Groups -> Administrative group name -> Server -> Server name -> Protocols -> SMTP
3. Right click on Default SMTP Virtual Server -> properties
4. Access tab -> Relay button
5. Select "only the list bellow" and add your domain and\or IPs you do want to allow the relay.
6. Check the "Allow all computers which successfully authenticate to relay, regardless of the list above" checkbox.

Allow Relaying on Exchange Server 2013

1. Open the Microsoft Exchange Admin Center then Open Mail Flow
2. Select Receive Connectors & Select the GFI FAXmaker connector
3. Select Scoping
4. Define the IP addresses or network range of the computers that will be using the GFI FAXmaker client/Fax Machines/Email Printers to send faxes.
Click the Add button under Receive mail from remote servers that have these IP addresses to add these IP addresses.
5. Enter the IP address range of the computers running the GFI FAXmaker i.e. Client, Fax machines, email printers.
For example or  


Error 550 is common in Exchange Server. It can be fixed using the above tricks on different version of Outlook, Exchange or SMTP Server.

I hope the above tricks help the user to fix error 550 in detail.
For any query or suggestion, do comment.


Post a Comment

Post a reply