In the last few weeks we have started seeing an increase in support requests relating to email delivery problems that are outside of the control of the MDaemon server. Specifically this happens when companies are relying on an ISP mail platform to provide POP3 mailboxes and SMTP services to deliver their mail to and from MDaemon. In this article I want to point out why the method you choose to get email in and out of MDaemon is so important and how you can redesign and often simplify your mail platform to minimise the effects of changes that are 'outside of your control'.

Over the last few months we have had an increasing number of support calls that relate to failing SMTP connections over Internet connections. This can happen on a range of network connections, whether it's mobile devices on 3G or home users trying to access their MDaemon mail server. Even businesses can find that they can no longer create outbound SMTP sessions on port 25 on their office broadband connections.

If you use our email server software, MDaemon Messaging Server, and you've ever called our support team with issues relating to being unable to send emails, you may have noticed that we often perform a spam blacklist check. To perform these checks we use just one of a range of useful tools over at the mxtoolbox.com website. We've been using this site for several years as in addition to the blacklist checking you can also do things like query a domain's Mail DNS and SPF records, check whether the SMTP port is answering and even obtain an explanation of message header information. An essential tool to add to your favorites if you are a mail administrator!

One of the more common customers support calls i get relates to MDaemon suddenly sending vast amounts of spam email. This floods the outbound Internet connection and everything crawls to a halt. Secondary to this the server's public IP address can get listed on various external SMTP blacklists which the customer then has to request removal from.