This solution is suitable if your requirement matches one or more of the following:

• You have a medium to large sized set of users (2000+).
• You would like to optimize on intra office traffic by hosting a mail server locally.
• Your infrastructure has strong high quality Internet links (with redundancy) and high performance WAN network links amongst the offices. It also has necessary redundancies to host a 24/7 setup.
• You would like total privacy and control over your email setup.

This server will be the MX server for the domain and receive mail from the Internet. This server will also be configured to deliver outgoing mail. The server will be configured to scan all incoming mail for Spam and virus using Spam Assassin, Clam AV, RBL, sender / recipient check etc.

The mail server will host the mailboxes for all the users on the domain. The end users will access their mailboxes using POP/IMAP/HTTP protocols. The address books will be accessed via the LDAP protocol and the web client-using http. In addition to the advantages of having an Internet mail server, having a separate relay server offers the following advantages:

• Any attack on the server from the Internet, in terms of a DOS/DDOS attack or a Spam/ virus attack will not affect the end user response.
• Also having two servers ensures that each can act as a standby to the other giving higher availability.

Incoming mail

• The mail for the domain will arrive at the relay server where they will be scanned.
• Valid mail will be delivered to the mail server where they are delivered to the users mailbox.
• End users access their mail boxes on the mail server.

Outgoing mail

• The users will configure their desktops to use the SMTP service on the mail server.
• Mail for other users on the domain will be delivered locally and mail for external domains will be directed to the relay server.
• The relay server will scan the mail and deliver valid mail to the Internet.

Both the MCS servers will be setup in an enterprise mode. In an enterprise mode, one of the servers is designated as the master and the remaining servers are configured as slaves to the master. User addition / deletion is done from the master. Setting the servers in an enterprise mode ensures that any changes made on any server are synchronized to all the other servers automatically. Some examples of auto data synchronization are as follows:

• User addition/deletion on master is synchronized to all the servers.
• A change in the directory information of a user, such as change in name address or telephone number, done on one server is synchronized to all the other servers automatically.
• Change in mailing information such as forwarding etc to synchronized to all the servers automatically.

Synchronization with the disaster recovery server.
In case of a DR server, the user configurations, server configurations as well as the mail store is automatically synchronized with the mail server at predefined intervals.

A separate Mithi Connect Server would be configured as a Disaster Recovery Server in a hot standby mode for the Mail Server.Data would be synchronized between the two servers. In case of any downtime to the Mail Server, users would access the DR Server. This would ensure minimum downtime.

Clients can access their mailboxes using a desktop email client such as Outlook Express/Outlook, Thunderbird etc. The protocol used to access mail can be POP or IMAP. Alternatively, users can access their mailboxes on the server using the web mail client