SMTP Authentication prevents unauthorized user from sending out spam mails. But some applications do not support SMTP Authentication. Example of these are web applications with mail sending features (Microsoft Office Sharepoint Server, PHP based applications, etc).

One solution to this problem is to bypass SMTP authentication for certain IP addresses. This article will show you how to configure Postfix to allow outbound mail without requiring authentication for authorized IP addresses.

Edit main.cf1. Edit the file /etc/postfix/main.cf and add the authorized IP addresses into mynetworks.
Edit main.cf2. Check the value of smtpd_recipient_restrictions to make sure that permit_mynetworks is the first value to ensure that nothing will prevent it from being restricted.
Service Configuration3. Restart the Postfix service or the MailScanner service if you have integrated MailScanner into Postfix.
Terminal4. Test Postfix by sending from the authorized IP address to an email address outside your domain.

Visit the forum to ask for help or to give a comment.

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Posted on 10/19/2008 and last updated on 11/6/2009
Filed under Postfix