Our take
Lexmark's U.S. record identifies part 36S0400 as the MS621dn. This monochrome printer offers up to 50 ppm Letter, integrated duplex, standard Gigabit Ethernet, and a recommended monthly range of 2,000–20,000 pages. Its 550-sheet tray and 100-sheet multipurpose feeder provide 650 sheets of standard input.
A wired office that prints mono documents at a steady pace and wants duplex without hand-feeding..
Choose an MFP if you need copy, scan, or fax, and do not assume built-in Wi-Fi without the optional card.
Pros & cons
What could work for you, and what to consider before buying.
What works in its favor
- Integrated duplex supports routine two-sided output without a separate add-on.
- The exact model has a 2,000–20,000-page monthly recommendation and a 50 ppm Letter rating.
- Gigabit Ethernet and USB are standard, with a useful multipurpose feeder.
What to weigh up
- This is a print-only mono device, not an all-in-one.
- Wireless is an optional internal card, so it is not standard Wi-Fi-ready.
- A specific used unit may not include the stated tray, supplies, or working duplex path.
The key details
| Model covered | MS621dn |
|---|---|
| Main functions | Monochrome print only |
| Print output | Up to 50 ppm Letter; 650-sheet standard input |
| Two-sided printing | Integrated automatic duplex |
Performance figures are manufacturer claims. Source checked October 8, 2026. Regional models and included accessories can differ.
What the features mean for you
A wired printer with a defined office range
Lexmark identifies the MS621dn as a monochrome laser printer for a medium workgroup. It is not an MFP: printing is the documented task, so copy, scan, and fax require separate equipment. The recommended monthly page volume is 2,000 to 20,000. This gives a useful context when comparing office devices, but it does not tell you how a particular used machine was maintained or how fast a mixed queue will run. The model is most persuasive when monochrome pages dominate and the team can use a wired network rather than requiring built-in Wi-Fi.
Automatic duplex helps with longer output
Integrated duplex is listed for the MS621dn, with Letter output rated up to 50 pages per minute simplex and 24 sides per minute duplex. That difference is useful to understand when duplex jobs become a regular part of the queue: page turning is automatic, but the per-minute figure is not the same for one-sided and two-sided work. For reports and internal packets, the built-in path avoids manual reloading. Ask for a sample both-side job on the specific device, since a model specification does not prove that a used duplex mechanism is clean or functioning.
A 650-sheet standard input reduces reloads
Lexmark lists a 550-sheet input drawer and a 100-sheet multipurpose feeder, for 650 sheets standard. The multipurpose path can be useful for occasional envelopes or other supported media while the main drawer holds everyday paper. Optional drawers can raise capacity, but they are separate accessories and should not be assumed in an offer. Check the 36S0400 part label and count the trays present. A 250-sheet output bin also needs to suit the job flow; capacity is only helpful when the machine's actual layout matches the office's document routine.
Ethernet is included; wireless is an option
The exact product record lists Gigabit Ethernet and direct USB, while wireless appears under optional network ports. That is a clear distinction for shared offices: wired network printing is standard, but Wi-Fi requires the compatible internal adapter. Do not let a listing use a general MS-series photo as proof that a specific dn unit has wireless. Confirm the installed accessory and test whichever connection the workplace expects. The current driver fit should also be checked for the actual computers, because the model page's older operating-system list does not settle support for every modern setup.
Separate the design from the offered machine
Lexmark marks the model discontinued. The specification still helps evaluate its intended speed, duplex, ports, and workload, but it does not tell you present stock, the remaining toner, or the state of a particular machine. Ask for the nameplate, page count, maintenance history, tray configuration, sample output, and return terms. The printer's substantial 650-sheet input and duplex design can suit a stable workgroup, while a small personal desk may prefer a quieter, simpler device. Make the choice around actual mono volume and the wired connection already available.
What else to compare
Compare the Lexmark MS817n for higher input and speed when duplex is not needed, or an MFP if document capture matters.
Before you buy
Does the MS621dn duplex automatically?
Yes. Lexmark lists integrated duplex for the exact model.
Is Wi-Fi standard?
No. Gigabit Ethernet and USB are standard; wireless is an optional internal card.
How much should it print each month?
Lexmark recommends 2,000 to 20,000 pages monthly; maximum duty cycle is a separate metric.
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. MS621dn exact-model product record ↗ — checked October 8, 2026.
- Lexmark U.S. MS621dn exact-model specifications: part, speed, duplex, ports, trays and volume ↗ — checked October 8, 2026.
The decision
The MS621dn balances fast mono output, built-in duplex, wired networking, and a documented medium-workgroup range. Its print-only and optional-wireless limits are straightforward.
Is it the right fit?
Check the exact model and today’s offers on Amazon.