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PHP Sendmail on IIS

Sun, 21st December, 2008 - Posted by Administration

Problems setting up PHP on a Windows server which is running IIS and also running a SMTP server inside IIS? Have you faced problems sending mail from PHP scripts running on IIS server with IIS SMTP engine?

By default IIS doesn’t allow relaying SMTP mails if it comes from 3rd party products. So this problem is related to IIS SMTP “Relay Restrictions”. Sometimes some of my clients are using PHP on windows servers using IIS 6 as the web server. In linux PHP supports native sendmail system from the OS itself. In windows you need to make PHP able to send out mail from localhost or change PHP to send using the SMTP host of your Managed Hosting company. If you are a .Net developer, you might already know that from ASP.Net codes or even Classic Asp code it’s just as simple as 1,2,3 to send out email or use the IIS local SMTP server. Let me make it simple for you, so that you guys can make use of the localhost server from PHP.

1 – Install and Configure IIS with PHP:
First of all install and configure PHP 5 as described in the PHP documentation. Try to avoid the windows based binary installer. Download the full package and install it manually.

2 – Test out PHP Pages:
Once you’re done with the installation. Test it out with a sample php info page. If PHP is able to execute the pages on the server then we are ready for the next step.

3 – Test email sending from PHP:
Now we need a test script to check whether we are able to send email using PHP. Here is a sample script that will aid you in this situation. Copy the content from this code and save it as email_test.php at your server root. Then try to run the file online (eg. if it’s returns “not ok” means you are not able to send email out. You can change the ‘’ into your email address so that you can receive the mail if it’s a success.

Contents of email_test.php:
echo(’not ok’);

4 – Configure PHP.INI for SMTP:
a. Stop IIS from the IIS Manager.
b. Now open your PHP.INI file. It could be on your C:\PHP folder or C:\WINDOWS folder. Depends on how you’ve configured IIS and PHP on your system. Once you’ve opened the PHP.INI file with notepad or something, search for the entry called “[mail function]” and set it as below.


c. Save and close the PHP.INI file.

5 – Configure IIS SMTP Relay Restrictions:

Once you’re done with PHP.INI, head over to Internet Information Services Manager. Assume that the IIS is running SMTP server also to send out email. You should be able to see the entry inside IIS manager stated “Default SMTP Virtual Server” or similar items. Now right click and access the properties page from “Default SMTP Virtual Server” as it’s shown below. 


On the properties page move to “Access” tab and click on “Connection” and you will be able to see which server/IP’s are allowed to make connection to the server. If “” IP is not there on the list, add it using the “Add” button, additionally you may also insert your server IP on the list.


Once you are done at the “Connections” window, click on OK button to accept the information. Now Click on “Relay” button at the “Access” tab and setup the relay options for the server. Grant the IP’s allowed to relay out mail for the mail server. Make sure “localhost” and IP “” are granted for relay, addition to that you can also insert your domain name and IP. 


Once you are done with “Relay Restrictions” window, click ok to accept the options and then click “Apply” and “Ok” button respectively to go back to the main screen of IIS Manager.
Now you can restart IIS from IIS manager.


Now for your testing run the emailtest.php file again. It should give you the response “ok“. If it’s not please check your SMTP configuration one more time along with PHP server settings and PHP.INI file.

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Category : Mail Support

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