POP3 Connector

The POP3 Connector is a piece of software included with Small Business Server versions of Microsoft Exchange Server that enables the server to fetch e-mail from external, 3rd party, POP3 servers.

The software can fetch e-mail on a per-user, per-account basis, or it can fetch e-mail from a catch-all account and distribute by the To: field based on the e-mail addresses assigned to users in Active Directory. Note that the latter method does not work for bcc'd e-mails and some mailing lists, as the recipient cannot be easily identified by looking at the e-mail headers. However, failed e-mail can be delivered to a central account, where the correct recipient can be identified manually and then distributed accordingly by the administrator.

The software is then scheduled to fetch e-mail at regular intervals, from once per hour to four times per hour. The schedule can be either continuous throughout the week, or vary depending on the time of the day and day of the week. If the situation requires it, an immediate download can be started from the configuration screen.

Alternatives
Other commercial alternatives are available that can be utilised for any version of Microsoft Exchange (or any RFC compliant SMTP server for that matter). These products typically provide increased functionality such as more frequent checking times (eg: once per minute) advanced logging and alerting, antispam/antivirus functionality, aliasing and content filtering. Free, open-source alternatives also exist.