Authenticated SMTP (SMTP AUTH)

Authenticated SMTP is a method of securing your SMTP server. With SMTP AUTH enabled senders who wish to relay mail through the SMTP server (that is, send mail that is eventually to be delivered to another SMTP server) must authenticate themselves to James before sending their message. Mail that is to be delivered locally does not require authentication. This method ensures that spammers cannot use your SMTP server to send unauthorized mail, while still enabling users who may not have fixed IP addresses to send their messages.

Mail servers that allow spammers to send unauthorized email are known as open relays. So SMTP AUTH is a mechanism for ensuring that your server is not an open relay .

At this time James only supports simple user name / password authentication.

Configuring James for Authenticated SMTP

Configuring James for Authentication SMTP is a multi-step process. It requires several adjustments of the config.xml. To enable SMTP AUTH, do the following:

First, as mentioned above, SMTP AUTH requires that James be able to distinguish between mail intended for local delivery and mail intended for remote delivery. James makes this determination by matching the domain to which the mail was sent against the <servernames> element of the James configuration block. Any local domains should be explicitly listed as <servername> elements in this section.

Second, James is configured out of the box so as to not serve as an open relay for spammers. This is done by restricting the IP addresses from which mail will be accepted using the RemoteAddrNotInNetwork mailet. This restriction must be lifted before users can send from arbitrary clients. To do this, comment out or remove the mailet tag containing the class attribute "RemoteAddrNotInNetwork". This tag can be found in the spoolmanager configuration block, in the root processor configuration.

Third, set the authRequired element of the smtpserver configuration block to "true".

Fourth, if you wish to ensure that authenticated users can only send email from their own account, you may optionally set the verifyIdentity element of the smtpserver configuration block to "true".

Fifth, restart James. This will pull in all of your configuration changes.

Verifying Your Configuration

Finally, you need to verify that your configuration was done correctly. This step is important and should not be skipped.

Verify that you have not inadvertantly configured your server as an open relay. This is most easily accomplished by using the service provided at will check your mail server and inform you if it is an open relay.

It is extremely important that your server not be configured as an open relay. Aside from potential costs associated with usage by spammers, connections from servers that are determined to be open relays are routinely rejected by SMTP servers. This can severely impede the ability of your mail server to send mail.

Of course it is also necessary to confirm that users and log in and send mail through your server. This can be accomplished using any standard mail client (i.e. Outlook, Eudora, Evolution).