SafeSecureMail.com Help/FAQ spam filters:

For the technically inclined, we use qmail, vpopmail, and maildrop with SqWebMail to make this all work.
Since we don't support end user login on our mail server, you will have to use the SqWebMail screens to maintain your mail filters.

If you don't see these links: "Edit Mail Filters" and "Edit Autoreplies" at the top of your webmail screen (between "Address Book" and "Log out") then shoot a quick email request to support@safesecuremail.com and request that we turn mail filtering on for your account.
Make sure you tell us your domain name and your email account name.
For example, to activate mail filtering for for john@worldsbestdomain.com the domain name is worldsbestdomain.com and the email account name is john.

Please note: if you receive mail for a non-existing account and you have one of your accounts selected for default delivery, these filters will not work for that mail.
The vpopmail default delivery mechanism bypasses the maildrop (filtered) account delivery.
We are working on a fix...

You create named mail filters for each account.
Each filter has a condition and an action.
These are extremely flexible. Over a period of time, we will document how to use each option.

Here are the two set ups you will probably want to use the most:

How to bounce mail from a specific email sender (or domain):
Create a descriptive (and unique) rule name.
Select Condition "Header".
Enter "From" (without the quotation marks) in the next text box.
Select "contains" from the next drop list.
Enter the specific email address or domain that you want to filter in the next text box.
If you want to see the incoming mail, select "Save in" in the Action section, and select the mail folder (I recommend "Trash") from the next drop list.
If you want to bounce the incoming mail, select "Reject with error" in the Action section.
Click on the "Submit" button, then click on the "Save all changes" button at the top of the screen.

How to bounce mail that has a specific word in the Subject line:
Create a descriptive (and unique) rule name.
Select Condition "Header".
Enter "Subject" (without the quotation marks) in the next text box.
Select "contains" from the next drop list.
Enter the specific word that you want to filter in the next text box.
If you want to see the incoming mail, select "Save in" in the Action section, and select the mail folder (I recommend "Trash") from the next drop list.
If you want to bounce the incoming mail, select "Reject with error" in the Action section.
Click on the "Submit" button, then click on the "Save all changes" button at the top of the screen.