Our take
Lexmark's MX421ade is a monochrome multifunction printer for an office that needs more than output alone. The exact U.S. product page identifies part 36S0700 and lists print, copy, scan and fax functions, automatic duplex, Gigabit Ethernet and USB. Lexmark rates it up to 42 pages per minute on Letter paper and recommends 1,000 to 10,000 pages each month. A 250-sheet tray plus a 100-sheet multipurpose feeder support different media in the normal queue. The page does not list built-in Wi-Fi for this model, so this is best considered a wired workgroup device. Buyers should compare routine workload with Lexmark's stated band and verify the offered unit's configuration and maintenance state.
A workgroup needing monochrome print, copy, scan and fax, Ethernet sharing, automatic two-sided output and a source-backed monthly workload band..
It is not for color output, built-in wireless, a very low-use desk that does not need an MFP, or offices that need a different scan-finishing workflow than the source documents establish.
Pros & cons
What could work for you, and what to consider before buying.
What works in its favor
- Lexmark identifies the exact 36S0700 model with print, copy, scan and fax functions.
- Automatic duplex and Gigabit Ethernet support a shared two-sided document workflow.
- The 1,000–10,000 recommended monthly range helps compare the model with office demand.
What to weigh up
- Built-in Wi-Fi is not listed; plan for a wired Ethernet or USB connection.
- The 250-sheet main tray may require frequent replenishment in a larger department.
- A listed speed and workload band do not reveal the condition of an individual printer.
The key details
| Model covered | MX421ade (part 36S0700) |
|---|---|
| Main functions | Monochrome print/copy/scan/fax; up to 42 ppm Letter |
| Print output | Automatic duplex; 250-sheet input plus 100-sheet multipurpose feeder |
| Two-sided printing | Gigabit Ethernet and USB; 1,000–10,000 recommended pages monthly |
Performance figures are manufacturer claims. Source checked October 6, 2026. Regional models and included accessories can differ.
What the features mean for you
A documented mono print, copy, scan and fax workflow
Lexmark's U.S. page identifies part 36S0700 as the MX421ade and lists printing, copying, scanning and fax. That combination can consolidate routine paper-document tasks for a smaller office without adding color capability that some teams do not need. Lexmark also describes color scanning even though the printer's output is monochrome; the finder profile concerns print color, so it remains a mono device. Confirm that the offered label says MX421ade and that the fax and document-feeder parts are present. Do not transfer features from a nearby MX-series model when comparing units ([Lexmark MX421ade product page](https://www.lexmark.com/en_us/printers/printer/11843/Lexmark-MX421ade)).
Use the monthly band to size the office routine
Lexmark recommends 1,000 to 10,000 pages per month for the MX421ade and rates output up to 42 pages per minute on Letter paper. The monthly band is a planning reference, not a requirement to print at the maximum or a promise about a used machine. Estimate actual routine volume, including peak periods, and compare it with the recommendation. The rated speed also does not guarantee that a mixed job with scans, copies or network traffic will finish at that pace. A business with very light use may find the workgroup chassis unnecessary; a larger shared queue should consider whether its peak load and service plan fit the product class.
Automatic duplex and practical paper feeding
The exact model page describes an integrated automatic duplex unit, avoiding the manual paper-turn process for routine two-sided output. Lexmark lists a 250-sheet input tray and a 100-sheet multipurpose feeder, which can separate ordinary paper from occasional special media. This can support reports and forms while leaving the feeder available for different stock. Verify that the duplex path and both feed sources work on any specific used device. The listed capacity describes the model's standard setup and should not be confused with optional tray capacity in a seller's broad family listing. If the printer is missing parts, the model specification alone does not establish what will arrive.
Wired network connection rather than standard Wi-Fi
Lexmark documents Gigabit Ethernet and USB for the MX421ade. Its standard connection profile supports a direct workstation link or a wired shared office queue. The exact page does not list built-in Wi-Fi, so a buyer should not treat the MX421ade as a wireless model because another Lexmark variant carries a wireless suffix. If a wireless network is mandatory, verify a manufacturer-supported accessory and the exact configuration before selecting. In a wired environment, also check driver compatibility, network policies and scan destination setup. A feature listing cannot confirm that a particular used unit still has working ports or current firmware.
Check document handling and service condition
A multifunction device introduces more parts to inspect than a print-only model: feeder rollers, scan glass, control panel, fax line path and duplex mechanism should all be checked. Confirm the page count, service history, error codes, sample copies and scans, and whether the supplied toner is usable. Lexmark's page describes the product configuration but does not report the condition, current price, stock, supply availability or seller policy for an individual listing. No personal hands-on test or buyer-review summary is represented here. For a daily office role, confirm return terms and the availability of a technician or replacement parts before committing the workflow to an older device.
What else to compare
Compare an MX-series model with a documented wireless configuration if Wi-Fi is essential, or a print-only mono device if copying, scanning and fax are unnecessary.
Before you buy
Does the MX421ade include fax?
Yes. Lexmark's exact U.S. product page lists printing, copying, scanning and fax for part 36S0700.
Can it print automatically on both sides?
Yes. Lexmark describes integrated automatic duplex printing for the MX421ade.
What monthly volume does Lexmark recommend?
Lexmark recommends a range of 1,000 to 10,000 pages per month for this model.
Is Wi-Fi built in?
The exact model page lists Gigabit Ethernet and USB but does not list built-in Wi-Fi.
Where can I check the current price?
Use the Amazon link for current offers. Check the exact model, seller, product condition, delivery, and return terms. This page does not display a live price or confirm stock.
Sources & review basis
We use the following manufacturer documentation for the product features above. Our suitability notes and buying advice are editorial judgments based on those features, not measured performance results.
- Lexmark U.S. MX421ade exact model page ↗ — checked October 6, 2026.
- Lexmark U.S. MX421ade identity, functions, duplex, ports and recommended monthly range ↗ — checked October 6, 2026.
The decision
The MX421ade is a strong fit when a wired office needs mono print/copy/scan/fax, automatic duplex and a published monthly band. Verify the exact part, feeder and service condition.
Is it the right fit?
Check the exact model and today’s offers on Amazon.