Letter Printing and Mailing Services

Guide: Lettershop Services in Detail

At Mail Processing Associates (MPA), our lettershop in Lakeland, Florida handles the physical assembly side of our direct mail work, from envelope inserting and machine folding to tabbing, label affixing, presort bundling, and direct induction at the USPS Business Mail Entry Unit (BMEU). MPA prints letters on its own presses, then assembles and mails them from the same Lakeland facility, with one project team and one chain of custody from data intake through USPS hand-off.

We have run this work for 35+ years, serving more than 700 lifetime business customers, and we mail from that one facility to all 50 states.

What a Lettershop Actually Does

A lettershop is a production facility specialized in preparing printed pieces for the mail. The work sits between the printer and the post office. A typical lettershop workflow takes finished printed components and turns them into USPS-ready mail trays and pallets. The core lettershop functions are:

• Inserting: Machine-feeding printed components (letter, reply envelope, reply card, brochure) into an outer envelope, then sealing the envelope.
• Folding: Folding letters, brochures, or self-mailers into the size and shape required by either the envelope or the USPS specification.
• Tabbing: Applying clear or printed wafer seals (tabs) to self-mailers and folded mailers so they meet USPS automation requirements.
• Affixing: Applying address labels, return address labels, indicia, postage stamps, or live stamps to the outside of the piece.
• Bundling and traying: Sorting prepared pieces into USPS-compliant trays, sacks, or pallets, and labeling them for the correct postal class and sort plan.
• USPS induction: Physically delivering the prepared mail to a USPS facility (BMEU, network distribution center, or destination delivery unit) with the proper paperwork.

If your printer hands you a stack of finished letters and envelopes and you do not know what to do next, that gap is what a lettershop fills. If your in-house team can fold and stuff a thousand pieces a week but cannot handle a one-time 50,000-piece appeal, that surge is what a lettershop absorbs.

In common usage, "lettershop" and "mailing house" are interchangeable: both mean the production facility that prepares printed pieces for the mail. "Lettershop" historically emphasized inserting and assembly, while "mailing house" emphasized presort, tray preparation and USPS hand-off. MPA does both in one facility, along with letter printing and data hygiene, so quotes for either cover the same scope of work.

We can run a lettershop-only job on print you brought to us, but we can also handle the printing, the data, the assembly, and the postal induction together, which usually saves handoffs, freight and time compared with splitting the work.

"The lettershop is where a campaign either ships clean or quietly falls apart. More than 35 years of running inserting and tabbing taught us that the discipline keeping a 4-piece package at exactly 4 pieces is the same discipline that keeps a tray from getting bounced at the dock."

Alec Boye, President, Mail Processing Associates

Lettershop Program Specifications

The specifications a marketing director or production buyer needs to compare lettershop vendors, in one table. Anything not listed is quoted per job.

Lettershop Services We Offer at MPA

Envelope Inserting

We insert packages into #10 (standard business letter), #9 (reply envelope), 6x9, 9x12, and booklet envelopes, by machine or by hand depending on the envelope and the components. Inserting jobs typically include a letter and a reply envelope, sometimes with a reply device or a brochure as a third or fourth insert.

Common inserting jobs we handle:

• Nonprofit annual appeals (donor letter, reply card, reply envelope, sometimes a premium)
• Membership renewals and dues notices
• Open enrollment and AEP packets for insurance and Medicare brokers
• Patient statements and EOBs for healthcare clients
• Government and municipal compliance mailings
• B2B prospect and customer mailings

Machine Folding

Folding turns a flat printed sheet into the size required by the envelope or by USPS for self-mailers. Our folders produce:

• Letter folds (tri-fold, c-fold, z-fold)
• Half folds
• Booklet folds for newsletters and brochures
• Double parallel folds for 4-panel pieces
• Right-angle folds for complex formats

Folding is typically priced per thousand pieces and depends on stock weight and fold complexity.

Tabbing for Self-Mailers

We tab letter-size self-mailers, folded brochures, and bifold or trifold direct mail pieces with clear 1-inch or 1.5-inch wafer seals so they stay closed in the mail stream. How the tab count and placement are set under USPS DMM 201 is covered in Self-Mailer Construction and Wafer-Sealing below.

Inkjet Address Printing and IMb

Where the address prints depends on the package. On window-envelope letters, the address block prints on the letter itself along with the personalization; on closed-face envelopes and self-mailers, we inkjet it onto the envelope or the folded piece. Each address carries the USPS Intelligent Mail barcode (IMb) and any optional human-readable elements (sequence number, scan line, personalized text). Production mail is inkjet-addressed rather than labeled wherever the piece allows; inkjet is faster, cleaner, and machine-readable.

Each mail piece carries its own IMb, each tray carries an Intelligent Mail tray barcode (IMtb), and each pallet carries an Intelligent Mail container barcode (IMcb). The electronic documentation (eDoc) filed with the postage statement links every piece to its tray and pallet, and USPS processing scans of those barcodes come back through Informed Visibility, so you can see your mail move through the postal network. Learn more about intelligent mail barcode solutions and how IMb data drives mail tracking and Informed Delivery campaigns.

Tray and Pallet Preparation

After address printing, pieces are presorted into USPS-compliant trays, sacks, or pallets and labeled for the correct postal class. We prepare First-Class Mail presort, USPS Marketing Mail (formerly Standard Mail), Nonprofit USPS Marketing Mail and Every Door Direct Mail (EDDM), and we run presort and commingling in-house to qualify mail for USPS automation presort prices.

Direct USPS Induction at the BMEU

MPA holds its own USPS mailing permit and enters its mail directly at the Lakeland Business Mail Entry Unit (BMEU). We hand prepared mail to USPS ourselves, with no separate mailing vendor or consolidator in between. For nonprofit and Marketing Mail, that removes a handoff from the schedule without paying for a faster postal class.

Get a lettershop and mailing quote today and we will quote the full per-piece cost including postage.

Match Mailing and Personalization Integrity

Match mailing keeps every personalized component in an envelope tied to the same recipient. It matters the moment a package carries a name, a personalized ask amount, an account number or a policy number: a donor named Maria cannot receive Maria's letter with David's reply card, and on a healthcare statement a mismatch is a potential breach of protected health information, not an embarrassment.

How we match depends on the package. When the letter is the only personalized piece and its address shows through a window envelope, the outer envelope is a generic shell, and the package runs on our Pitney Bowes DI2000 inserter in record sequence. Packages with a personalized closed-face envelope or several personalized inserts are matched by hand. Either way, the personalized components print in the same record sequence, and sample packages are checked against the record list during the run.

Match mailing comes up in nonprofit appeals with personalized ask strings, insurance and Medicare AEP packets, patient statements and explanation-of-benefits (EOB) mailings, membership renewals with member-specific dues, and government notices tied to a parcel or account. We run all five under SOC 2 Type 2 audited controls, with HIPAA-compliant handling wherever protected health information is involved.

"Match mailing is where a careless lettershop turns a compliance mailing into an incident. Pairing the wrong reply card with the wrong donor is sloppy; pairing the wrong statement with the wrong patient is a reportable event."

Cat Boye, Head of Commercial Operations, Mail Processing Associates

Self-Mailer Construction and Wafer-Sealing

A self-mailer is any piece that travels through the mail without an envelope: a folded brochure, a bifold or trifold flyer, a folded newsletter. Self-mailers are popular because they remove the cost of an outer envelope and the inserting step, but they introduce a different problem. USPS automation equipment runs at high speed, and an unsecured folded piece can flop open, jam the sorter, and damage other mail. To prevent that, USPS requires folded self-mailers to be sealed shut, with tabs (also called wafer seals) or glue.

The tab specification is easy to get wrong, and a wrong one can cost a self-mailer its automation price. The number of tabs, their placement (leading edge versus trailing edge) and their size (1-inch or 1.5-inch) depend on the piece's final size, weight, paper and fold orientation, and under DMM 201.3.14 the tabs must not be perforated. A trifold sealed with one tab on the wrong edge can be downgraded to the non-automation rate, and USPS can refuse a mis-tabbed mailing at acceptance until it is re-tabbed, which costs the in-home date.

We set the tab count and placement from the finished dimensions and fold under the current USPS DMM 201 self-mailer rules, confirm the specification on a finished piece before the tabbing run, and check tab placement on the sample pulls that also check fold direction and address legibility. The sample in your proof shows where the tabs land.

"Tabbing looks like the cheapest step in the job, so it is the step people get wrong. A few minutes spent on a finished sample protects the automation price on the whole mailing."

Alec Boye, President, Mail Processing Associates

Why MPA Beats Splitting Print and Lettershop Across Vendors

If you are considering using one company for print and a different company for lettershop, here is what splits typically cost you.

Your Data Is Read Once

When the printer, the lettershop, and the mailing list provider are three separate companies, the same data has to travel through three different file formats. Address files get re-exported, re-mapped, and re-sequenced. Each handoff is a chance for sort order to break (mail is not in tray order), for column mapping to fail (FirstName ends up in the Suffix field), or for a record to drop. A single integrated print-and-mail vendor like MPA reads the data once, sequences it once, and prints in mail sort order so the lettershop work feeds straight into trays.

One Project Team Owns the Date

In a 3-vendor split, when the mail does not drop on the day you expected, each vendor tends to blame the next one. Print blames data, lettershop blames print for being late, mailing house blames lettershop for missing the postal cutoff. With MPA, one project team owns the date from the moment we receive the file to USPS acceptance, and because we prepare the presort and the postage statement ourselves, a question at acceptance comes straight back to the team that built the mailing.

One Quote for the Whole Job

When you split the job across vendors, each one quotes their slice. Print quotes the printing, lettershop quotes the inserting and tabbing, mailing house quotes the postage. The hidden costs come in the gaps: freight from the printer to the lettershop and on to the post office, plus file conversion and sort fees. MPA sends one written quote that covers every step from data receipt to USPS hand-off.

Real Numbers on Lettershop Pricing

Lettershop pricing depends on the work involved. These are MPA per-piece ranges for the most common lettershop steps alone, not including print or postage.

These figures cover lettershop labor and machine time; the low end of each range is the 100,000-piece volume and the high end the 5,000-piece volume. Every job is priced in a written quote that separates lettershop labor, print, mail services and postage, and the Postage Basis table below lists the current Mixed-tier letter rates.

Postage Basis Under USPS Notice 123

Postage appears on its own line of the quote and the invoice. These are the Mixed-tier letter and postcard rates from USPS Notice 123, effective July 12, 2026, for pieces presorted and entered at the BMEU. First-Class runs under 500 pieces mail at single-piece prices, $0.78 for a metered 1-ounce letter. Against that metered price, presorting a 10,000-letter First-Class mailing at the $0.707 Mixed price saves about $730 in postage. USPS Marketing Mail letters can also earn destination-entry prices, while First-Class Mail has no entry discounts. Flats are quoted per job.

Common Lettershop Job Types We Run

Nonprofit Annual Appeals

The classic nonprofit fundraising letter. Outer #10 envelope, 1- or 2-page letter (often with a personalized greeting and ask amount), a reply card, and a reply envelope. Sometimes a premium (address labels, a small calendar, a sticker sheet). Pieces ship in waves leading up to year-end giving deadlines, with calendar-tight production windows.

Why MPA: the appeal can mail on our USPS permit imprint or yours, and healthcare-affiliated donor data gets HIPAA-compliant handling. See our nonprofit direct mail services page for the full workflow.

Insurance and Healthcare Compliance Mailings

Patient statements, EOBs, AEP packets, open enrollment notices, policy renewals. These mailings have hard regulatory and calendar deadlines. The cost of a late drop is not just a marketing inconvenience; it can be a compliance event.

MPA is HIPAA-compliant for protected health information handling and SOC 2 Type 2 audited. Our HIPAA-compliant mailing services workflow puts the chain of custody in writing, from data receipt to USPS acceptance.

B2B Prospect and Customer Mailings

Account-based marketing dimensional mailers, customer reactivation campaigns, conference invite packages. Smaller quantities (often 200 to 5,000), more elaborate formats (boxes, oversized envelopes, kits), tighter personalization. The lettershop work here is hand assembly as often as machine inserting.

We handle both: the machine-inserted letter drop and the hand-assembled C-suite kit with 7 components inside a custom box. Pricing scales with complexity, and we can also handle B2B direct mail strategy end to end.

Government and Municipal Notices

Hearing notices, tax bills, water system updates and voter information mailings. These run on tight statutory windows and require evidence of mailing for audit purposes.

MPA is a Florida State Term Contract 80141800-25-STC vendor (Mail Processing) and a Veteran-Owned Small Business. We are commonly used by government and municipal clients for compliance-driven mailings where chain of custody matters more than per-piece price.

Real Estate and Local Service Saturation

Postcards for real estate farming, HVAC and home services seasonal campaigns, and restaurant menu mailers. These typically run as Every Door Direct Mail (EDDM) or as addressed saturation Marketing Mail at the carrier-route level, which we recommend for most route-level mailings.

Our EDDM services include route planning, prepress, print and USPS entry. The lettershop work for EDDM is straightforward (no inserting, no addressing), but the bundling and entry paperwork is exacting, and our team prepares it routinely.

Lettershop Quality Controls

Lettershop work is detail-intensive. The failure modes are not subtle: a missing reply card sinks a fundraising appeal, a mis-tabbed self-mailer can be rejected by USPS, and a mislabeled or out-of-sequence tray can hold up the whole mailing at acceptance.

Sample Pulls and Pre-Induction QC

Our Pitney Bowes DI2000 folds and inserts the machine-run packages, and sample packages are pulled and inspected during the run and again before any tray leaves the lettershop floor. We verify insert count, record match on personalized packages, fold direction, tab placement, address legibility, IMb readability, and tray label accuracy. If a sample fails, the run is paused and the cause is corrected before more pieces process.

"A house-list appeal earns roughly 5 to 9 percent response when it lands right (ANA Response Rate Report), and a missing reply envelope puts that response at risk. A fundraising letter with no way to give wastes the postage and the ask, which is why insert count is the first thing every sample pull checks."

Cat Boye, Head of Commercial Operations, Mail Processing Associates

Lettershop Glossary

• BMEU: Business Mail Entry Unit. The USPS acceptance facility where permit holders present commercial mail for verification and acceptance. See USPS PostalPro for USPS business mail acceptance resources.
• IMb: Intelligent Mail barcode. The 65-bar barcode that identifies each mail piece for USPS automation prices and processing scans.
• DMM 201: USPS Domestic Mail Manual Section 201, the physical standards for commercial letters, cards and flats, including the sealing rules for folded self-mailers.
• NCOA: National Change of Address. The USPS database of address changes filed in the last 48 months. NCOA processing matches your list to recent moves.
• CASS: Coding Accuracy Support System. The USPS standardization process that brings addresses into compliant format and applies ZIP+4.
• DPV: Delivery Point Validation. A USPS code (Y, D, S, N) that indicates whether an address can actually receive mail.
• Mixed: The USPS postal sort tier for letters that are presorted but not deeply sorted to the destination. The minimum tier for letter-class automation discounts.
• EDDM Retail: The USPS Every Door Direct Mail Retail program, which lets businesses mail to every address on selected carrier routes without a mailing list. MPA mails EDDM under its own permit rather than through a retail counter.

Where to Verify These Credentials

• SOC 2 Type 2. Controls observed operating over an audit period, Vanta-managed and audited annually. Report available under NDA through the MPA Trust Center.
• HIPAA-compliant handling. Protected health information handled under documented safeguards, with a Business Associate Agreement in place first. Policies summarized at the Trust Center.
• Florida public entities. MPA is a Florida State Term Contract 80141800-25-STC vendor (Mail Processing). The public record is linked on our government print and mail page.
• Since 1989, one facility, all 50 states. Veteran-Owned Small Business. 5.0 stars across 100+ verified Google reviews on our Google Business Profile.

Get a Lettershop Quote Today

If you are evaluating lettershop vendors, send us your specs: email or call with the format, quantity, data source, and target mail date, and we will respond with a per-piece cost for the lettershop work, the postage, and (if applicable) the print.

• Phone: 863-687-6945
• Quote request: mailpro.org/contact/
• Schedule a call: mailpro.org/schedule/
• Location: 430 N Wabash Ave, Lakeland, FL 33815