We want Rossum to be your universal Document Gateway. Send in whatever you want, and Rossum will know what to do with it. We built Rossum to digest and process various document and file types that arrive as attachments to your emails. However, it may not be able to handle all of the emails and attachments that you want to process. That is where our Advanced Email Filtering extension becomes so useful.
What is the Advanced Email Filtering Extension, and how does it work
There are rules for Attachment filtering right in Rossum (such as filtering out images smaller than 100 x 100 px). Still, in case you want to tweak it further to the types of documents you receive, we brought you the Advanced Email Filtering function in Rossum Store.
This extension allows you to filter out documents from incoming emails based on the following rules:
- Email subject contains a specific text
- Email content contains a specific text
- Type of document (for instance filter out all but invoices)
- Number of pages in the document (min/max)
- Document dimensions (height/width)
- Document filename contains a specific text
What does this mean for you?
The email will still appear in your Rossum Email Dashboard, but Rossum will not process the attachments filtered out by your rules. This way, you can save money by not processing unnecessary documents because we won’t add them to your Rossum billing.
How to set up the extension
Watch the video guide below or read on.
Step 1: Activate Advanced Email Filtering function from Rossum Store
To activate this function:
- Click on the Extensions tab at the top of the app.
- Click on the Rossum store option to display all the available extensions.
- Select the “Advanced Email Filtering” extension tile.
- Click “Try extension.” to add this to the “My extensions” tab.
Step 2: Specify to which queue(s) you want to add this extension
You should see the “Rossum Store extension settings” window now.
Scroll down to “Queues” and select the queue(s) to which you want to add this extension. Remember to save your changes once you’ve chosen the queues you want.

Step 3: Customize the filtering rules
In the same “Rossum Store extension settings” window, scroll down to “Configuration,” and you will see the parameters in JSON that you can edit according to your needs. You will probably need to do this as this configuration is very company specific.

In the table below, you will find all the parameters you can set and their description:
Parameter name | Description | Supported values |
Document size | Specify the minimum width and height in pixels the allowed incoming document should have. Rossum will filter out anything less than this. | Number (integer) |
Document length | A document should have a minimum and a maximum number of pages to be accepted. Anything below the minimum and above the maximum is filtered out. | Number (integer) |
Accepted mime types | Specify the mime types which should be accepted (such as PDF, PNG, XLSX). File types not stated here will be filtered out. | Any mime type (see the list of Rossum accepted mime types) |
Subject ignore patterns | Use regular expressions to specify what kind of text patterns are illegal in your workflow. If an incoming email has a subject containing any text pattern stated here, all its attachments will be filtered out. | Any regex rule |
Filename ignore patterns | Use regular expressions to specify what kind of text patterns are illegal in your workflow. If an incoming file has a name containing any text pattern stated here, it will be filtered out. | Any regex rule |
Email content ignore patterns | Use regular expressions to specify what kind of text patterns are illegal in your workflow. If an incoming email’s body contains any text pattern stated here, all its attachments will be filtered out. | Any regex rule |
Step 4: Try it out!
It’s now time to put the extension to the test! Send an email with attachments to the queue that has the extension enabled. Try to send something you allowed and something you forbade using the rules and see how it gets filtered.
Cool, right?
Optional: Tweaking the function
We designed our extensions in the Rossum Store not only to help you solve your business challenges but also to inspire you to create your own! Therefore, you can view the extensions’ code and copy it into your function.
