How to use the Junk folder in Shinymail

We've been providing spam filtering on our email service for some time, ensuring that you never even see 95% of the unsolicited messages that are sent to your mailbox. Unfortunately it's hard to block all the spam without accidentally blocking ligitimate email too, so a small amount of spam will always get through. This article looks at how you can sort most of this spam into a separate "Junk" folder.

Every message received by our mail servers is passed through a number of processing stages before it's finally delivered to your mailbox. One of these is a product called Spamassassin. Spamassassin (SA) uses a large number of tests in order to give each email a score, which determines how likely it is that the message is spam. Scores below 0 are almost never spam (sometimes called ham), while scores above 10 are guaranteed to be spam. The problem is the messages with scores between these two values.

Messages with scores above 5 are almost always spam, but on rare occasions a valid message will receive a score above 5. So to avoid the chance of legitimate email being rejected we let message with scores between 5 and 10 through, but we mark the email with an "X-Spam-Level" header containing the score as a number of asterisks (*). For example X-Spam-Level: ****** means that the message scored 6.

Your email client can then use these scores to automatically sort the messages into a "Junk" folder, allowing you to check for the odd mistake without filling up your Inbox with spam.

To do this using Shinymail, you need to create a filter. First log into your account at and click on "Filters" in the left hand menu.

This shows you the list of filters that are run on email when it is delivered to your mailbox. We're going to create a new Spam rule by clicking on the "New Rule" button.

Fill in the following information:

  • Rule Name: Spam
  • Select a field: X-Spam-Level

Now select "Contains" and type "*****" in the text box (5 asterisks).

For "Do this:" select "Deliver to Folder", and select your Junk folder from the list. If you don't have a Spam or Junk folder, you can select "Create a new folder" to create one.

Finally click "Save" and your done.

Now, whenever a message with a score of 5 or more is delivered to your mailbox, the filter will automatically move it to the Junk folder!



Am I mistaken in saying that unless you are using IMAP (or the Shinymail webmail interface only) you may not see these junk mail messages unless you actively log into Shinymail?

In the past I have created these rules for Outlook users for client-side filtering. Also there is the setting in the Thunderbird menu for
Junk mail controls > Trust junk mail headers set by "Spamassasin" which is quite interesting.

Yes, that's correct. The Junk folder is not visible to POP3 users as POP3 only downloads the contents of the Inbox. Client side filtering is probably a better choice if you only use POP3.