Such a misconfiguration can lead to the mail server being listed in databases of known open relays, such as ORBS . This presents a problem if the server is then relaying through a legitimate mail server, such as Access Communications' mail server. Landing such a high traffic mail server in ORBS can result in a loss of e-mails by users. The following are a list of links we have compiled for securing some of the popular mail server products against spam via open relay. All of the below links are hosted off-site, and are provided for mail admins' convenience only.
Most links are to official documentation written by the software vendors, where possible.
The information provided at these links is not supported by Access Communications Internet. Upgrade to Exchange 5.5 SP2 or later. Upgrade to Sendmail 8.9.3 or later.