boklm's weblog

Why you should never use IMail from Ipswitch

I had for my work to administer an IMail v8.05 mail server, from Ipswitch, and I can say now that I've seen that, that no one should use that program in any as it is the worst email server program I've ever seen or imagined (however I have to admit I never saw the IIS SMTP service from Microsoft). Here are the main reasons why this program should never be used :

• The developers obviously didn't read the RFC 1893 or 3463 when they created the IMail program, and they didn't understood that when a server answer with an Error code starting with the number 4, it is a Persistent Transient Failure, not a Permanent Failure, and sending again in the the future the same message may be successful. Due to their poor error handling and their misunderstanding of the RFC, the only action they take when they encounter this kind of error is to bounce the message to the sender with a stupid "user unknow" message, without any other detail of course and no retry. Knowing the fact that most spammers won't take the time to send again their message when they receive a temporary some people had the idea to use a method called Greylisting to block a significant amounts of spam by first rejecting an email from an unknown server with a temporary error, accepting and adding the sending server to a whitelist when it try to send again the same email after a certain amount of time. The spams are then rejected while the emails sent using a regular email server are received. The problem is that the IMail server doesn't handle this correctly, this means that you won't be able to send any email to a server using greylisting.
• When an email cannot be delivered, for any reason, the error message sent to the sender is always the same : "unknown user", even if the error has nothing to do with an unknown user (timeout connecting to the destination server, over quota, etc ... there can be many reasons why an email connot be delivered). As a result it's difficult to know why you receive an error message.
• The server crashed for no reason and needed a reboot very often to fix some problems.
• All the configuration and management of accounts is done using a Graphical User Interface. The configuration is saved in the Windows Registry or binary configuration files. As a result it is very difficult to write a script to make changes on an important amount of accounts or parameters at the time, you have to do it using the GUI, one item at the time. It makes it also very difficult to keep backups, or prepare a migration to an other email system. But it seems actually to be the regular things for a Windows program.
• The GUI program allow you to crash the whole mail server in a few clicks if you don't take care, without any way to come back using the GUI options. It happenned to me once, and I had to modify some obscure undocumented parameters directly in the registry in order to fix the problem (I was lucky to find this, most people just format and reinstall).
• The program lacks many options, and is not modular. For example it is not possible to add external spam filters, add special routing instructions, add greylisting. You are limited by the features the developers of the program decided to include (but it seems to be also the case for most Windows programs I saw).
• It's completly unreliable
• And of course this shit is far from being free !

So unless you want to lose mails, have something completly unreliable, don't want to be able to keep backups easily or to be able to migrate you config to an other server easily, I strongly discourage you to ever use IMail ... 5 months ago I couldn't imagine something like that could exist.

(this text is a part of my internship report)