Enterprise class anti spam filter includes POP3 Gateway™ POP connector and email retriever.


Download email from a POP account directly into Microsoft Exchange Server (or any SMTP mail server), while filtering spam and protecting your server against dangerous exploits


POP3 Gateway™ started it all. It is the POP3 downloader that finally provided reliable POP3 retrieval to organizations without a dedicated Internet connection and IP address. It is responsible for thousands of Microsoft Exchange Server installations in non-dedicated environments. Without POP3 Gateway, these organizations would have been without email.

Since it's original release in 1997, POP3 Gateway™ has continued to evolve and offer greater and more complex functionality. It is no longer just the best and most reliable POP3 connector / downloader / retriever available for Microsoft Exchange Server 5.5 , 2000 and 2003. It also provides industry leading spam and malicious email content filtering.

EMP is recommended by all the major email server vendors. Major organizations throughout the world are using EMP's email content filtering to protect their enterprises from spam, dangerous exploits and phishing attacks. Now you can enjoy this enterprise class security for your system within a POP3 download architecture.

EMP is not limited to working with only Exchange Server. It will download email and protect any SMTP compliant mail server. This includes Microsoft Exchange Server (all versions), IBM / Lotus Domino and Notes, Novell GroupWise, MailEnable, IMail, Sendmail, Merak, Kerio, etc...

Extensible Messaging Platform ( EMP 7), will download pop email, stop Exchange spam, phishing attacks and email borne viruses before they reach Exchange Server or the organization's employees and customers.




The Problem

The extended SMTP command ETRN as described in RFC1985 and implemented in Exchange Server 5.0 beginning with Service Pack 1, is an attempt to address the inability of the SMTP protocol to function over dial-up connections between SMTP servers. In theory, an ETRN configuration attempts to provide the equivalent of an on-demand, dedicated connection between the two SMTP servers.

However, theory doesn't always mirror reality. There can be serious consequences for those unaware of the potential danger of implementing this ill-fated approach. The most serious of these consequences include the unfettered access by Internet hackers to a company’s internal LAN.

Also, most ISPs and hosting services are less than enthusiastic about providing ETRN capability to their customer base. In fact, most will not provide it because of the risks to them.

Most organizations considering ETRN, are doing so because of the cost savings of a dial-up or ISDN connection versus a dedicated line or because DSL is not available in their area. Often these organizations are small Businesses or home offices that are typically ill-prepared for the substantial expense associated with addressing the same security risks they would face with a dedicated line.

The Solution


ETRN problems are eliminated with a POP3 Gateway based e-mail solution.

POP3 Gateway can be installed anywhere on your network. It is logically positioned between your mail server (Exchange Server, GroupWise or Domino) and the Internet. With POP3 Gateway installed on your network, your mail server can receive Internet e-mail via a standard ISP PPP connection with a dynamically assigned IP address.

Even with a dedicated connection, POP3 Gateway is a more secure e-mail solution. It permits your mail server to transparently receive incoming Internet e-mail, while remaining safely behind your firewall. Your mail server is no longer required to allow direct Internet connections from un-trusted sources. This is why many organizations, while having dedicated Internet connections for web browsing, are still not willing to take the risk of direct Internet connectivity to their mail servers (particularly Exchange Server and its well-published security problems). These organizations depend on POP3 Gateway as a front-end for their mail servers providing them with a more secure Internet e-mail architecture

Major Security Hole

Your mail server (with your organization's proprietary e-mail) and local systems are vulnerable to Internet attack

ETRN requires a dedicated IP address, instead of the safer dynamically assigned IP address, which is an ISP's  normal, more secure PPP configuration.

Extensive security procedures including costly firewalls are now required for your internal systems identical to those required for a dedicated Internet connection.

SPAMMERS can hijack your SMTP port for their outgoing SPAM e-mail while your system is connected to your ISP.

Hackers can easily gain access to your private internal network and compromise your proprietary data and the integrity of your critical systems.

This is how it can happen!

  1. Hacker sends This e-mail address is being protected from spambots. You need JavaScript enabled to view it an extremely large e-mail message.
  2. This will hold the unsuspecting organization's communication line open to the Internet for an extended period of time.
  3. There is now a dedicated network connection open to your private network via your fixed IP address for fun-n-games from anywhere on the Internet.

Headache for those who send you mail!

ETRN takes advantage of misusing the ISP's Mail Server queuing mechanism which is intended only to provide a fail-safe for a temporarily failed communications line. During network outages when the dedicated communications link to the recipient domain is unavailable, the mail is queued and delivery is retried later. When this mail cannot be delivered, messages are sent back to the sender announcing that the mail could not be delivered. If the connection is not restored within a period of time the mail is returned to the sender as a failed delivery. This queuing mechanism is also not real efficient, but for its intended purpose it doesn't have to be. However, when this queuing system is abused by the use of ETRN, besides creating an excessive load on your ISP's system, your customers, friends and business associates sending your domain mail messages, may often receive automated delay and failure notices from your ISP's mail server because of this method of mail queuing.

ISPs don't want it either!

Overloads ISP available bandwidth

The requirement for a dedicated IP address at the customer’s site allows anyone on the Internet to connect to the customer’s server. Providing inbound access to a customer’s server from multiple clients on the Internet can substantially increase the load on the ISP’s network resources. This additional system load decreases the ISP's performance and increases their costs.

ISPs and hosting services are already configured for a standard mail queuing mechanism POP3, most have no desire to incur the costs of fundamentally changing their systems to support one which is less desirable.


If you find an ISP who's willing to offer it, you probably should question their expertise!

The smaller ISP that unknowingly may be willing to configure for ETRN support is probably not going to provide the level of service or performance required to be the candidate of choice for hosting your corporate web site or routing your domain's e-mail

Extensive investment – even without dedicated communications line.

Firewall server  - $$$ - Just as if you had a dedicated SMTP connection.

Security personnel - $$$ - Just as if you had a dedicated SMTP connection.

Proxy Server - $$$ - Just as if you had a dedicated SMTP connection

BOTTOM LINE - ETRN is Costly, Insecure and a bad idea.

Complete POP3 Gateway Information - Including free download

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POP3 Gateway™ is a trademark of J.A. Korsmeyer, Inc.


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