Mercury is a simple yet robust mail solution ideal for the small and medium sized companies. Running the server requires minimal maintenance and the GUI interface makes it easy for non-tech person within the company to upkeep the simplier tasks like add, changing and removing users, backing up and cleaning up logs, adding additional domain etc.
Prior To Setting Up Mercury
It is advisable to setup Mercury on a machine that is running on Windows NT/2000/XP Pro or Server. Also to set it up on a NTFS partition to prevent snooping on emails by anyone who is at machine curious enough to go through the hard disk and opening up files within the mail folders.
Windows 2000 and XP also consist of IIS (Internet Information Services) which we can configure later to run Squirrel Mail which will serve as the web interface for Mercury.
Ensure that the authoritative DNS servers for your zone (yourdomain.com) is currently resolving correctly and pointing to the public IP address that the machine that you are intending to run Mercury is located.
If you are behind a NAT router, you will need to also make sure that traffic coming in from port 25 (SMTP' 110 (POP3'143 (IMAP) and 80 (HTTP) are being directed to your server. Port 110 and 143 are required to be opened if you are using a mail client to access your emails via POP3 or IMAP. Port 80 is required to be opened if you are using an web browser to check your emails from the Squirrel Mail interface.
Setting the MX records for your domain is just a convention. Not all mail server will obey MX settings. Some will connect directly to yourdomain.com and attempt delivery to it.