The following content was forwarded to me by Saurabh. Originally written by Shuvam, this article brings out the differences between Postmaster and Mtracks, and is really very informative. I thought that it would be a good idea to put this content here so that everyone benefits.Â
1. Postmaster handles only email, while Mtracks handles Web access too.
   This alone is the largest difference between the two, and this makes
   Mtracks much more well suited to small offices.
   Once this difference is highlighted, all the features from the
   "Mtracks Features Summary" white paper related to the Web access and
   proxy control can be explained to the client.
2. Postmaster works (primarily) on Windows PCs, while Mtracks works on
   Linux. The added security, virus-resistance, stability, and
   reliability of Linux is an added benefit in the Mtracks solution.
3. Postmaster usually works on Windows desktop OS, which are specially
   insecure and unstable. It is also possible to make Postmaster work
   on Windows server class OS, e.g. Win2K3, but then the licence fees
   of Win2K3 becomes quite high. Mtracks on the other hand works on
   Linux, which is a server-class OS to begin with, and has no separate
   licence fees for Linux.
4. Postmaster does not have a browser-based administration interface;
   all administration typically has to be done sitting at the console
   of the computer which is running the Postmaster software. This is
   not necessary with Mtracks; you can manage it sitting anywhere.
5. Postmaster fetches emails only through POP3 accounts which are set up
   on some ISP's server. If your office has a permanent IP address and
   leased Internet link, in theory it can receive direct incoming
   emails from the Net, but Postmaster cannot handle this. You are
   forced to receive mails via a POP3 account somewhere on some other
   server totally unnecessarily. Mtracks can fetch messages from POP3
   accounts as well as receive direct email.
6. Mtracks gives the customer the option of receiving compressed UUCP
   email. UUCP over TCP allows incoming email to come in via Starcom's
   MX servers, without the customer needing a POP3 account anywhere or
   a permanent IP address. UUCP is much more reliable than POP3 mail
   fetching, and large messages (greater than 20MB) can easily come in
   over UUCP even if the Internet link breaks in between. When fetching
   mails from a POP3 mailbox, if the connection breaks in the middle of
   a large email, the entire message has to be re-fetched, thus wasting
   time and money and blocking up the subsequent messages. With UUCP,
   the system restarts the download at the point where the connection
   broke.
7. Mtracks keeps all metadata in a relational database. This allows
   future integration of this data with ERP systems, billing systems,
   etc. One of our clients is building a large set of business
   applications including financial accounting systems, for internal
   use. They want to use the Mtracks database for user authentication
   and password validation for all these applications, so that a sort
   of single-signon and a unified user database is possible.
8. Mtracks provides IMAP4 support, which Postmaster does not. IMAP4
   allows all users to keep their mail folders, including old mails, on
   the server. This means that valuable mails don't get lost when a
   desktop's hard disk crashes. It also means that a user can move from
   one desktop to another and still access all his mails, because they
   reside on the server.
9. The Webmail feature on the Postmaster system is of very little use.
   It can only show you the new messages in the Inbox, but can't let
   you access the old messages which are there in the rest of the mail
   folders, because Postmaster does not store old messages and user
   folders on the server. All these folders are forcibly kept on the
   desktop computer's hard drive. With Mtracks, you get IMAP4, where
   you can store mail folders on the server, and all these mails can be
   later viewed, forwarded, or replied to using Webmail.
10. Mtracks provides a LDAP-based address book for users. This address
   book can also contain external email addresses for outside parties,
   thus allowing a common enterprise-wide address book. Postmaster does
   not provide an address book at all.
11. Mtracks provides you a vacation facility, wherein a user can set up
   an automatic response to all his incoming messages when he is away
   from office (typically on vacation, hence the name of the facility).
   Postmaster has no such feature.
12. Mtracks has a reminder feature, which Postmaster does not have. We
   have usually found that reminders are a very powerful feature which
   users become totally dependent on, once they begin using it.
13. Password change reminder and expiry: Mtracks sends a reminder to
   users who have not changed their passwords for a long time. The gap
   duration after which these reminders are sent can be set by the
   system administrator. If the user does not change his password after
   repeated reminders, his account can be blocked automatically by
   Mtracks. This is an important security feature. Postmaster does not
   have any of these features.
14. An Mtracks server can act as a file and print server, where the
   userID and password which is used for email can be used for
   accessing a user's files too.
15. Mtracks supports auto-collection of email addresses, a feature which
   is not provided by Postmaster.
16. Mtracks provides an anti-virus scanner as part of the package, while
   this is a separately priced option with Postmaster.
17. Mtracks servers can be set up to work in redundant pairs. In this
   situation, one server will be active (or primary) and the other
   will be in backup mode. The backup server will periodically pull out
   all data from the primary server and make a mirror copy. This works
   automatically. If the primary server fails, the backup server can be
   made primary in about three to five minutes, and email services can
   continue. Postmaster has no such feature.
18. Starcom provides the services of incoming mail reception through its
   MX servers, and outgoing mail transfer through its outgoing SMTP
   servers. These services have various advantages like bandwidth
   conservation, and can address many situation which would be
   problematic with more conventional solutions like Postmaster.
In summary, Postmaster appears to be a sort of toy application, not
really designed for large enterprise use. An organisation which becomes
a mature user of email will typically begin to demand greater features,
greater control, and greater integration than what Postmaster provides.
Mtracks is a better answer.