To activate the spam scanner, first choose Use Spam Scanner. You find this setting under the project > Settings > Email.
You should then choose what scanner to be used depending on which one works best for you.
This happens in the email ticket engine when you have activated "use Spam Scanner":
- All incoming emails will be scanned for spam using these settings, then one of these two options will occur:
- All emails that are NOT considered SPAM will be imported into VisionFlow.
- All Emails that are considered SPAM will be stored in the folder "Mail" --> "Spam" in the document tab (only visible for Admins and project admins) as .eml files.
To force-import emails that are categorized as SPAM even though you do not consider them to be, all you have to do is to move them into the "Mail" --> "Not spam" folder in the document tab and they will be automatically imported into VisionFlow the next time the mail importer job is run for your project.
Note that emails from unknown users (depending on the "Only allow emails from existing users/companies" settings) are not imported from the "Not spam" folder if you have "Only allow emails from existing users" and "Only allow emails from existing companies" checked. If you only have the "Only allow email from existing users" the email will be imported if you move it from "Spam" folder to "Not Spam" folder.
Note that the emails that originate from a user that is in the system are not scanned.
Below you'll find a short description about the different filters available for use:
Performs a heuristic scan of the message contents looking for defined spam patterns.
Scan for anomalous characters
Looks for strange characters which when found in excess often indicate spam.
Use HTML concealment scanner
Detects the presence of HTML concealment. This plugin actually just accesses data determined by the HTMLParser used by the engine.
Scan for invalid attachments
Looks for attachments with unusual or dangerous file extensions.
Scan for invisible mails
Simply looks for messages without content or subject.
Scan for obfuscated characters
Looks for characters which have been misused to represent legitimate characters, such as '@' in place of 'A'.
Use "Robinson" chi based spam scanner
The main chi square probability scanner based on the ideas of Gary Robinson.
Use image dominance scanner
Looks for unusual ratios of images to text. This is intended to catch spam emails which use solely images to convey their message.
Blacklist email marked as spam
Put in the email addresses (comma-separated) from which you wish not to import emails, but to treat them as Spam at once. You can also use a wildcard prefix, such as *@somespamdomain.com.
Use keyword scanner
Performs a simple keyword match against the tokens returned by the tokenizer. In the lower text field, you can put in "Killer words", ie one word is enough for the email to be treated as spam.