Our client is one of India's leading garments export groups. They manufacture and supply ready-made garments to some of the world's best-known international brands, and are India's premier player in the garments exports business. They have five factories in two countries employing 3000-4000 thousand workers. Their estimated annual turnover is about INR 500 crores (about US$ 120 million).

This organisation depends heavily on email for communication with overseas clients. If an important email is lost in transit, they have on occasion lost upward of USD 10,000 in increased expenses towards order fulfilment. Email delays exceeding 12 hours get escalated to their Managing Director.

They have opted for a secure and reliable email infrastructure at their HO in Mumbai. We entered this relationship in 1997, and set up an initial email server infrastructure by customising the configuration of Linux-based software to suit their needs. At that time, Merce did not exist.

Today their email and controlled Web access setup is based on Mtracks, the single-server version of Merce. It runs on a pair of redundant firewalls and a pair of email servers, all running Linux on Intel-based hardware. The current installation is the third incarnation of their email infrastructure, starting with the first setup in 1997. All of these have been implemented by Merce PSG. Each incarnation included re-architecting the hardware and upgrading the software of their email server and Internet connectivity setup, to take into account changing needs.

Their Internet link has a static IP address and receives incoming email directly from the outside world. Their own firewall is their highest priority MX for email reception. The Internet connection is kept alive for about twelve or thirteen hours every working day; internal servers are shut down when the HO closes for the night. Complex internal aliasing rules distribute incoming email to different sets of people, so that email received to a role account is always answered promptly by one of the members in that role.

In case of Internet link failure, a backup path for email is provided by routing through mail re-routing servers operated by Merce as a service. In those situations, the company connects to the Internet using a temporary dialup connection or DSL link and uploads and downloads messages with our servers. This adds only a minute or two to the end-to-end mail transfer latency and is completely transparent to end-users.

Users away from the office access their email using Mtracks' HTTPS-based Webmail interface. Remote offices and factories too access email this way. Recently, more than forty laptop users have been given VPN-based connectivity to the internal mail servers. This allows them to use their normal mail client applications instead of Webmail, and connect securely to their mail accounts in their HO over the Internet from anywhere in the world. Some members of the company's top management travel outside the country for more than ten days every month, and this VPN-based mail access is their lifeline.

Filtering for email-borne viruses and worms was earlier provided by using a commercial anti-virus solution on the firewalls. This has since been replaced with Merce's built-in virus filters. Infected documents and messages are "quarantined" in a separate area on the firewall while disinfection is attempted. Since the filtering is on the firewalls, internal email traffic within the organisation is not filtered. On a typical day, the HO receives between 9,000 and 17,000 spam messages which are detected and diverted by Merce's spam filters.