Server-based software

Server-based software can run on your mail server or on a separate machine. Acting as a gateway against unwanted messages and attachments, it checks for e-mail from known spammers and filters messages based on e-mail headers and transport information. These products are usually priced on a per-server or per-mailbox basis.

lvetica">Product	Works with	Notable features
Baltimore MailSweeper for SMTP	Microsoft Exchange, SMTP	LDAP integration. Policy management for senders and recipients.
Baltimore MailSweeper for Exchange	Microsoft Exchange	LDAP integration. Policy management for senders and recipients.
Baltimore MailSweeper for Domino R5	Lotus Domino	LDAP integration. Policy management for senders and recipients.
CMS Praetor for Lotus Domino	Lotus Notes	Uses real-time blackhole lists to identify known spam domains. Requires subscription to MAPS.
CMS Praetor for Microsoft Exchange Server	Microsoft Exchange	Uses real-time blackhole lists to identify known spam domains. Requires subscription to MAPS.
Elron IM Message Inspector	Lotus Notes, Microsoft Exchange	Analyzes the context of messages and ranks their relevance. Built-in Web-based reporting.
GFI Mail Essentials	Lotus Notes, Microsoft Exchange	Quarantines messages with macros. Approval of quarantined messages via moderator client or e-mail client. Archives e-mail in an ODBC database.  Download demo
Lyris MailShield	Lotus Notes, Microsoft Exchange, Sendmail	Links to MAPS or ORBL. E-mail filter management via Web browser.  Download demo
Marshal MailMarshal	Lotus Notes, Microsoft Exchange, SMTP	Archive unpacking: Scans multi-level .zip files. Supports MAPS. Usage reports. LDAP support.
NAI WebShield SMTP	SMTP	Remote management via SMTP client. Auto virus definition updates. Statistics on number of e-mails scanned, infected, and filtered for content.
SurfControl SuperScout E-mail Filter	Microsoft Exchange	Transmits non-essential e-mail after business hours. Remote administration.
SurfControl SuperScout E-mail Filter SMTP	SMTP	Transmits non-essential e-mail after business hours. Remote administration.
Sybari Antigen 6.2 for Microsoft Exchange	Microsoft Exchange	Multiple scan engine support. Scans multi-level .zip files. SMTP and M: drive scanning. Deleted files replaced with customizable text file.
Symantec Mail-Gear	SMTP	Multithreaded SMTP mail handler. Supports Eudora and Netscape Mail. Supports e-mail scanning in Microsoft Word, Microsoft Excel, PowerPoint, text, and Adobe PDF.
Symantec Norton Antivirus for Gateways 2.5	SMTP	Norton AntiVirus Extensible Engine technology. Automated macro-virus analysis and repair.
Trend Micro InterScan VirusWall	SMTP	Scans SMTP mail, and HTTP and FTP traffic. Optional blocking of Java applets and ActiveX objects. Removes macro viruses. Customizable warning messages. Prescheduled pattern file updates.

The following services block spam before it reaches your mail servers, saving your bandwidth for bona fide messages. Filtering options, available statistics, and Web interfaces vary. Some services let you choose whether to block spam or send it to an administrator. Most of these services don't require that you install dedicated hardware or software at your site. Some services also offer virus protection.

Product	Notable features
BrightMail Anti-Spam	Samples spam sent to over 100 million e-mail addresses. Staff push spam-blocking rules to dedicated servers at your site. Web-based interface. Anti-virus available.
Mail-Filters.com	Message backup. No hardware or software installed at your site.
MessageLabs SkyScan AS	Spam can be blocked or sent to a system administrator. Via the Web-based management interface you can select which IP addresses, domain names, and specific e-mail addresses to block.
Postini Junk Email Assistant	SMTP statistics. Systemwide alerts. Centralized management of applications. No hardware or software installed at your site.
Singlefin Email Gateway Services	Automatic filtering to separate inbox. Web-based control panel. Message backup. Virus protection via Sophos and Trend Micro. No hardware or software required at your site.
Syntegra eMail Sentinel	Works with any SMTP messaging server. Sendmail-based SMTP router. Centralized server-based tools that protect against Internet spam attacks. Web administration tools.
United Messaging Message Control	Automatic filters for Reverse DNS, MAPS RBS, MAPS DUL, and MAPS RSS. Virus scanning.

Hardware-based e-mail screening gateways can handle a higher volume of e-mails than their software brethren. These appliances sit between your router and mail servers. Some scan both outbound and inbound mail, others only inbound messages. Filtering rules vary, based on content or behavior, such as determining that a remote host is an open relay. Additionally some of the devices scan for viruses.

Product	Notable features
8e6 Technologies ES2000 Spam Filter	Rules based on user groups. "White lists" of acceptable addresses or domain names.
Escom ASMTP Appliance	Company's ASMTP technology runs as a proxy server daemon on Linux. Handles both SMTP and Extended SMTP messages.
McAfee WebShield e500	Scans SMTP, HTTP, FTP, and POP3. SSL Web-based console for remote management.
Mirapoint Message Director	Outbound message content filtered to enforce corporate policies. Can be managed via HTTPS Web interface, command line interface (CLI), or Java GUI. Integrates with LDAP servers.