If your organization serves the Orthodox or Charedi community, there’s a good chance a significant portion of your audience uses an internet filter. NetFree, Rimon, and similar kosher internet filters are standard in many frum homes and workplaces — and they can block, distort, or flag emails that weren’t designed with these systems in mind.
This isn’t a niche technical detail. It’s a core deliverability issue that determines whether your message reaches your audience or disappears into filtered obscurity.
How Kosher Internet Filters Work
Services like NetFree (widely used in Israel and among Israeli-origin communities), Rimon (common in Charedi communities), and TAG (the Technology Awareness Group’s filtering service) operate as network-level filters. Unlike spam filters that screen email content after it arrives, these kosher filters:
- Screen all internet traffic at the DNS or ISP level
- Block or restrict access to domains not on their approved list
- May strip images from emails if the image-hosting domain isn’t whitelisted
- Block click-through links if the destination URL isn’t approved
- In some configurations, route email through filtered servers that inspect content
The result: an email that looks perfect in your preview might arrive broken, image-free, or completely blocked for your filtered subscribers.
The Problem with Standard Email Platforms
Mailchimp, Constant Contact, SendGrid, and similar platforms were built for mainstream commercial audiences. Their infrastructure includes:
- Image hosting on domains not whitelisted by Jewish filters
- Click-tracking URLs that pass through their servers (often not filter-approved)
- HTML templates with external resource calls to CDNs not on kosher filter lists
- Tracking pixels hosted on commercial analytics domains
None of this is a problem for their intended audience. For a shul sending a weekly newsletter, or a yeshiva announcing registration, it means a meaningful portion of your community never receives what you send.
What “Filter Compatible” Actually Means in Practice
A truly filter-compatible email platform does several things differently:
1. Domain Whitelisting
The sending domain, image-hosting domain, and click-tracking domain must all be either whitelisted by major kosher filter providers or structured to avoid filter triggers. KosherEmail maintains active relationships with filter providers and ensures our infrastructure is on approved lists.
2. Link Structure
Click-tracking links (which marketing platforms use to measure who clicked what) typically route through a tracker domain. If that domain isn’t approved, filtered users who click a link see an error page. Filter-compatible platforms use approved tracker domains or structure links to minimize filter friction.
3. Image Handling
Images hosted on non-approved CDNs are simply invisible to filtered users. A beautiful email design becomes a text-only block. Filter-compatible sending either hosts images on approved infrastructure or designs templates that remain meaningful and complete even without images.
4. Content Screening
Some filter configurations screen for specific content categories. Legitimate organizational emails should pass these checks, but the content and template structure must be clean.
Who Is Affected
This matters most for organizations whose audience includes:
- Charedi and Yeshivish communities in Lakewood, Monsey, Boro Park, Flatbush, Baltimore, Chicago, and similar centers
- Israeli Charedi communities — NetFree penetration in Israel is extremely high among Charedi families
- Modern Orthodox families using TAG or similar filtering services
- Yeshiva families and kollel families — filter adoption in these demographics is very high
If you’re a mosad in Lakewood or Bnei Brak and you’re using Mailchimp, you may be reaching less than 50% of your intended audience.
How to Audit Your Current Email Program
Not sure if you have a filter problem? Here’s a simple test:
- Send your standard email to a test address that runs through NetFree or Rimon
- Check: Do images appear? Do links work? Is the formatting intact?
- If any element is missing or broken, you have a filter compatibility issue
Alternatively, survey your community. Ask in your Shabbos announcements: “Do you receive our weekly email properly?” The answers may surprise you.
The KosherEmail Solution
KosherEmail was built specifically to address this problem. Our platform:
- Uses infrastructure that has been vetted and approved by major kosher filter providers
- Designs templates that maintain their integrity even when images are filtered
- Structures links to minimize filter friction while maintaining accurate analytics
- Tests all sends against common filter configurations before delivery
- Provides ongoing monitoring to ensure continued filter compatibility as filter software updates
For organizations serving the frum community, this isn’t optional — it’s the baseline requirement for effective communication.
Beyond Deliverability: Trust and Community Standards
There’s a dimension to this beyond pure deliverability. When a community organization uses a platform that bypasses or conflicts with the community’s chosen filtering standards, it sends a message. Using filter-compatible infrastructure signals that you understand and respect your community’s values and technology choices.
This is especially relevant for mosdos — yeshivos, Bais Yaakovs, and community organizations. Your communication infrastructure should reflect your community’s standards, not work against them.
Questions about whether your current email setup is filter-compatible? Contact our team for a free audit.