The Case of the Mysterious Mail Delay

I spent the afternoon trying to diagnose some email problems on a client’s LAN. They have a mixed environment of Windows and Unix servers. Their internal DNS server is a Windows 2000 box. Their external DNS server and email server are Red Hat Linux boxes. Sometime yesterday, for no apparent reason they began experiencing a 30-45 second connection delay between the email server and their email clients (mostly MS Outlook – yes, I’ve warned them that Outlook is the single biggest propagator of viruses in the known Universe but they still use it).

We checked all the usual suspects. No DNS problems, no recent changes to BIND or, no sign of DoS attacks, rootkits, viruses, etc. I’ve seen a similar problem caused when the Timeout.ident value in Sendmail is set too high but this was not the problem either. For now, it’s a mystery but further experiments will hopefully turn up the cause.

IT Culture Clash

I’ve spent much of the week doing on-site work for a client (thus the lack of time for news posts this week!). The customer is a medium sized company created by several smaller companies that merged. They’re assembling an IT department from the combination of Unix, Mac, and Windows boxes that came from the smaller companies. A few of the suits predictably brought up the issue getting rid of the “non-standard” equipment (i.e., the Macs and Unix servers). Among the issues that came up were why we would want to use sendmail when “everyone else in the world” uses Microsoft Exchange. The sheer stupidity of this statement caught me a bit off guard but I did a little research and found a web site that does a regular survey of Internet SMTP servers. It’s a lot like the Netcraft survey of web server software (Apache is up to 62.53% this month, by the way). The SMTP server results are much the same as those for Apache. Sendmail has a current market share of 52.3%, followed by “other/unknown” at 8.8%, and further down the list is Microsoft (including Exchange) at a whopping 4.4%. Unfortunately there are no graphs to show changes in market share over time like Netcraft does. In fact, while the SMTP survey is a great idea, Sirana hasn’t done nearly as cool of a job of implementing it as Netcraft did.