In DirectAdmin Linux shared hosting servers, Relay access denied error is a common email issue reported by web masters. Over time, Bobcares help desk support services devised procedures to resolve such issues in less than 10 minutes, and to an extend, prevent these issues from happening.

Relay access denied error means, the server is refusing a mail to another server from a domain owner’s email client. The mail server is unable to confirm whether the domain owner is authorized to send emails THROUGH it. Exim mail servers of DirectAdmin distinguish a valid sender when it gets a valid SMTP or POP/IMAP login from the domain user.

Following are the two main causes of Relay access denied errors, and how we manage them:

1. When the authenticated IP changes on mobile devices

In servers that are configured with POP before SMTP, domain owners with mobile devices report intermittent relay errors. This happens when they change the WiFi hotspot or their 4G/3G/2G network changes their IP due to a break in coverage. The DirectAdmin email server would be referring to the old IP as the authenticated one, while the domain owner’s mobile device would be using the new IP address.

We prevent these issues by enforcing SMTP password authentication in DirectAdmin servers. For this we just disable da-popb4smtp by deleting the default values for hostlist relay_hosts in /etc/exim.conf, and restarting Exim.

2. When the domain owner tries to connect to the wrong server

This situation happens with newly registered domain owners. They would either try sending mails before the account setup is complete, use their ISP’s mail servers, or keep using their old hosting server’s host name or IP address. Since the change needs to happen at the domain owner’s device, we focus on lightning fast resolution using step-by-step instructions customized for their mail client. We maintain a repository of step-by-step email configuration settings for all mail clients, in all popular operating systems and mobile devices. So, we are able to usually give a resolution in as little as 10 minutes.
Email issue volume and type can vary from one web host to another. If you would like to discuss how to better manage the support traffic for your shared web hosting, we would be happy to talk to you.

About the author

Visakh S is a senior software engineer at Bobcares. He has extensive experience in managing technical support teams of web hosting companies and data centers. He has been instrumental in devising support strategies to reduce recurring complaints, and improve support responsiveness.