- Fully featured and scalable
- runs on a wide variety of platforms
- straightforward Web-based administration interface
- full version is freely downloadable (adds banner to all messages until paid-for).
- Relatively expensive
- help isn’t context-sensitive.
CommuniGate Pro is a step up in terms of cost – it starts at $499 (~£310) for up to 50 users and five mailing lists. But it offers a working Web interface, so that remote users can log in via the Web from anywhere, as well as just about any forwarding or distribution option you could possibly want. It also runs on more than 30 different computing platforms, so it would be difficult to find a system that couldn't run it.
Like the other MTAs reviewed here, CommuniGate Pro lets you set up mailboxes, redirect email and set aliases. One useful function is the ability for a single user to subscribe to more than one mailbox, so that, for example, you could create a public mailbox for mailing lists and a private one for close contacts, and unsubscribe from the public one when you’re on the road and want just the most urgent stuff.
As you’d expect, CommuniGate Pro supports external spam filters and virus scanners. It has integrated support for real-time black-hole lists (RBLs, valid domains or origin), and facilities to run additional helper applications (such as SpamAssassin, which takes a little effort but is worth it). You can also set system-wide or account-specific additional rules, so that email meeting your particular specifications is discarded, forwarded to an account set up to trap trash, or bounced back.
People vary greatly in what they find intuitive, but CommuniGate Pro seems the simplest and easiest to understand of the three MTAs reviewed here, and is the most fully featured. The administration interface is Web-based, and does a good job of organising the software’s many options into logical categories. Even so, if you haven’t run a mail server before you’ll find it takes some time to get up to speed with CommuniGate Pro -- if only because there are so many options. The built-in help is excellent at explaining how and when to use each feature -- our one complaint is that because the documentation is external rather than context-sensitive it can be difficult to find the bit you need. The interface divides server administration into four sections: settings, accounts, domains and monitors. You can specify access rights separately for each.
CommuniGate Pro is freely downloadable in a full version; until you’ve paid to register it, the software adds a one-line banner to messages advertising that fact. This corrupts some attachments in some mail readers, but is otherwise no trouble and gives you the chance to take as long as you want to set it up and ensure it does the job you need before paying. The server runs on over 30 different platforms including all the Linux and UNIX variants, Mac OS X and Windows; an older version runs on older Mac OS versions. Calendaring facilities (both Web-based and Outlook-compatible) are available, and improved address books are in the works. CommuniGate is expandable for increasingly large enterprises by adding servers and licences -- useful if you’re a small business now but have aspirations and want to be able to grow smoothly.