UniSent   
http://victori.hypermart.net

Suppose you have Outlook 2000/2002/2003 users who access additional mailboxes (usually info@company.com, sales@company.com, support@company.com etc.) on an Exchange 5.x/2000/2003 server (other mailbox setup in the Microsoft ExchangeService). When they reply to or forward from that mailbox the message goes into their primary (usually personal) mailbox sent items. UniSent utility lets the message to stay in the mailbox that it originated in (i.e. sent item goes to Sent Items folder of the mailbox the item was sent from). The license based on the number of users that actively use the product. 5-licenses pack costs $200; 10-licenses pack costs $350; unlimited pack costs $1500.

Express Plus   
http://www.ChaosSoftware.com

Business email client with mail-merging for bulk personalized mailings and powerful Bayesian mail filtering to learn what messages you consider to be spam and keep them out of your inbox. Express Plus does not use a database to hold your messages, but instead stores each message as a unique individual file on your PC. Besides having no problem with database corruption, this method allows any active-scanning anti-virus program to work more effectively to prevent infection of your PC by cleaning, quarantining or removing messages with viruses before you or another user can click on them (and this doesn't require your anti-virus software to use any specialized mail add-ons to protect you). Express Plus can send personalized email to your contacts with mail merge templates you create (no more "Dear Friend" letters!) and can manage up to 250 different mail groups. This program also offers shared mailboxes that can be opened by multiple users at the same time on a network. It supports multiple e-mail accounts in one mailbox, has the ability to read messages live on your server without downloading (using a feature called Server Headers), provides easy access to reading email headers, plain text version, html version, or the attachment list of an email, supports POP3, SMTP, and LDAP servers, and as an option, Express Plus can be combined with the powerful Time & Chaos information manager to offer a complete and integrated package.

wodMailbox   
http://www.weonlydo.com

WeOnlyDo! Mailbox is a component that can be easily integrated into your applications to provide full management over mailboxes and message parsing. Using wodMailbox, you can easily access mailbox, count messages, look at messages, count parts, save attachments, look at headers, delete messages etc.. When wodMailBox opens mailbox, it expects to find there either regular mailbox just as is used on UNIX systems (one file with full mail messages one after another) or just one message inside, just as Outlook Express saves .eml files. When you need to parse received messages, it might be hard to check all the possibilities that one simple mail message may contain. We all used to receive simple email messages - few headers and body text. But, sometimes you get attachments, multipart messages, different encodings and stuff like that. It's almost the same for wodMailbox - it's light, quick and fully supports all mail related RFC's. You can look on using wodMailbox for three main purposes: When you want to access mail messages in the mailbox When you want to access and parse one mail message When you want to prepare and create new message Using together with wodPop3Server and wodSmtpServer (or any other UNIX-alike server) you will notice that easiest way to store messages on per-user basis in files. So, one file contain all the messages for one user. If user moves to different computer or account, it's easiest this way to move his email also. Moreover, IMAP and similarly 'larger' protocols keep all the mailboxes this way - all users' messages in one file, on per-user basis. Once you want to access such mailbox, you just pass it's reference to wodMailbox.Filename property, and call Lock method. At this moment, wodMailbox will open the mailbox and count all the messages for you, but trying to use as low amount of memory as possible. This way, it can open and parse large mailboxes (few megabytes is considered to be 'small' at this point) with ease.