
Automatic letter opener (milling cutter) · Martin Yale
Martin Yale PostMark 3078
Speed: 20,000 envelopes per hour (production); 36,000 per hour (theoretical) · Maximum thickness: .25" (6 mm) auto feed; .39" (10 mm) manual feed
Listed on the manufacturer's website (source, as of Oct 18, 2026)

Where to buy
Machines in this class are mostly sold and serviced through the manufacturer's authorized dealers. We didn't find an Amazon listing for this exact model with a current offer. We don't show prices; ask a dealer or check the retailer for the current price.
Specifications
| Brand | Martin Yale |
|---|---|
| Model | PostMark 3078 |
| Type | Automatic letter opener (milling cutter) |
| Cutting method | Milling cutter; depth of cut 0.7 mm (factory set), 0-3 mm (tool adjust) |
| Speed | 20,000 envelopes per hour (production); 36,000 per hour (theoretical) |
| Daily volume | Up to 60,000 filled envelopes |
| Feed | Hopper capacity 300; feeder capacity 100 envelopes; mixed-thickness separator |
| Maximum envelope length | 13" (330 mm) |
| Maximum thickness | .25" (6 mm) auto feed; .39" (10 mm) manual feed |
| Screen | 3.8" (96.52 mm) touch screen |
PostMark is Martin Yale Industries' letter-opener and addressing brand ("Postmark by Martin Yale Industries").
Values as published by the manufacturer, in its own units. Fields the manufacturer doesn't state are left out rather than estimated. Shown without scores or rankings.
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