Case Study

Scaling Labs

High-volume outbound. Replacing catch-all resolver.
Method: API, bulk processing. Emails tested: 2,000+

"You made it into my production stack. That setup is cheaper than my old plan and recovers ~7% more sendable leads."

“Matched accuracy at a fraction of the price and roughly 20x faster — minutes vs 1.5h queue. Per-email reasons beat binary verdicts. The API is clean and the bulk resolve flow was easy to automate. I’ve subscribed.”

Albert Zussman

Scaling Labs

Background

The Setup

Before filtrat, the stack was MillionVerifier for first-line email verification and Scrubby for catch-all resolution as a second pass. The system worked but Scrubby was slow (1.5 hour queue) and expensive.

The test: run filtrat against real sending data with known bounce outcomes.

Methodology

The Tests

What was tested across 2,000+ real emails:

Catch-all emails

334 emails — head-to-head vs Scrubby

Known hard bounces

814 emails — with known bounce outcomes (ground truth)

General inbox

500 general-inbox emails

Personal B2B

800 emails — vs MillionVerifier

Head-to-Head

Catch-All Comparison

Metric	Filtrat	Scrubby
Bounce rate on "valid" verdicts	3.64%	3.69%
Processing time	Minutes	1.5 hours
Per-email reasoning	Yes	Binary only
Price	Fraction	Full plan

Matched

Scrubby's catch-all accuracy

0x faster

Minutes vs 1.5 hour queue

~0% more

Sendable leads recovered

Fraction

Of Scrubby's cost

The Switch

Before / After

Before

Scrubby

1.5 hour queue

Full plan price

Binary verdicts only

After

Filtrat

Minutes

Fraction of the cost

Per-email reasoning

Result

~7% more

Sendable leads recovered

Lower total cost

Subscribed. In production.

Results

Key Numbers

Emails tested	2,000+
Catch-all accuracy vs Scrubby	Matched (3.64% vs 3.69%)
Speed improvement	20x
Additional sendable leads	~7%
Per-email reasoning	Yes
Outcome	Subscribed. In production.

Takeaway

The Bottom Line

Filtrat matched Scrubby's catch-all accuracy at 20x the speed and a fraction of the cost. A high-volume sender tested it on 2,000+ real emails with actual bounce data, put it into production, and subscribed.

200 free credits.

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