Where things go wrong with a mailing is almost never due to the printing.
A direct mail campaign consists of three components: the creative, the data, and the postal mechanics. While most attention is directed toward the creative aspect, most failures stem from issues with the data and postal mechanics.
This guide covers the data and mechanics involved: what a mailing list should look like, how format choices impact postage costs, and the sequence that ensures a mailing stays on schedule.
Get the data right first
Nothing else can begin until the list is finalized, because the quantity determines the print run and the postage estimate.
What a usable list looks like
- One record per row, with each element in its own column: title, first name, surname, organization, address lines, postcode, country.
- Consistent formatting throughout, rather than having some rows with the full address crammed into one field.
- No blank rows, no merged cells, and no notes within the data.
- A unique reference is assigned to each record, allowing any individual piece to be traced.
- A stated date of last update
Problems tend to concentrate in lists compiled from multiple sources, as each source may have its own conventions. This consolidation work must occur either before the file is sent or after, and it is far cheaper to do it before.
Cleaning: the steps that pay for themselves
- Deduplicate. Not just exact matches. The same household appearing as two slightly different spellings is the common case.
- Validate addresses against a postal address file so formatting and postcodes are correct.
- Remove known bad records: gone-aways, previous returns, and anyone who has opted out.
- Fix capitalisation. Names in full capitals or all lower case look automated and undermine the piece.
- Check the salutation logic. Missing first names produce letters addressed to "Dear ," which is worse than a generic greeting.
Each returned item costs you the printing, postage, and handling, without delivering any value. On a list that hasn't been cleaned in a couple of years, the proportion of outdated records is usually higher than most people expect. Cleaning the list is the cheapest improvement available for a campaign.
The format of a mailpiece affects postage more than its weight does.
This is where budget surprises often arise. Postal pricing is categorized based on size, thickness, and weight. These categories have strict boundaries. Even a small discrepancy, such as a few millimetres too long or a millimetre too thick, can push a piece into a higher, more expensive category. This change can significantly alter the cost of the entire mailing.
Points to consider before finalizing the design:
- Dimensions against the size bands, with the aspect ratio limits that some services apply
- Thickness, which is easy to exceed with a multi-component pack or a heavy insert
- Weight, including the envelope, every insert and any attachment
- Flexibility, since some rates require the item to bend, which rules out rigid enclosures
- Sealing method, as some services have requirements about how the item is closed
Calculate the postage band before finalizing the format. Then, design the piece to comfortably fit within the band rather than at its edge. A design that fits exactly to the limit will fail if the paper is slightly thicker than specified.
Bulk rates and what they require
Postal services provide discounted rates for volume mailings, but these discounts are conditional. The conditions usually include a minimum quantity, sorting the mail by destination, applying specific marks or barcodes, and providing advance notice of the dispatch.
The requirements are specific and they change, so confirm the current rules for your service before committing. What matters at planning stage is that the discount is not automatic: the mail has to be prepared in a particular way, and that preparation is part of the fulfilment work rather than something that happens at the post office counter.
If your volume is just below a certain threshold, it may be worth checking whether a modest increase in quantity reduces the total cost. It sometimes does.
Addressing: printed or labelled
There are two approaches, with a clear practical difference between them.
Printed directly onto the envelope or the piece. Cleaner, no label edge, and no separate application step. Requires the envelope to run through the press, which limits some materials and finishes.
Applied labels. More flexible, works on any enclosure, and allows the mailing to be assembled before the data is final. Adds a step and a visible label.
A windowed envelope with the address showing through from the letter inside avoids both, and removes a matching operation entirely, which reduces the risk of the wrong letter reaching the wrong person. Where the pack has multiple components, the assembly considerations are covered under kitting and fulfilment.
Personalisation beyond the address
Variable content within the piece, such as a named salutation, a local branch address, or a personalized offer, all run on the same data. Each additional variable field is another potential point of error, so it's important to keep the number of them proportionate to the value they add. Additionally, specific attention should be given to checking the exception cases.
A sequence that holds together
- Week one: agree the format, check it against postal bands, confirm the rate that applies
- Week two: assemble and clean the data, deduplicate, validate addresses, confirm the final count
- Week three: artwork finalised and proofed, including a personalised sample using real records
- Week four: print, assemble, address
- Week five: sorted, presented and despatched, with a despatch notice where the rate requires it
- After: record returns and update the list, so the next mailing starts cleaner
The proof step deserves careful attention: proof with real records, including the awkward ones. For example, a long organization name, a hyphenated surname, a missing first name, and a four-line address can each reveal a layout problem that a tidy sample record will not.
Running a mailing with us
We take the list, clean it, and deduplicate the records. We then report back on what we found before anything is printed. This includes details on how many records were removed and why. This report is often useful in itself, as it reveals the true state of your data.
We verify the format against current postal requirements during the quoting stage. This ensures that the postage figure in your budget is the amount you will pay.
Send us the format you have in mind and a sample of your data, and we will come back with a print and postage estimate together. See related work under printing services, deadline options under express and fast printing, or get in touch through the contact page.
The short version
First, settle the data because it determines the quantity and postage. Clean and deduplicate the data before printing, as each outdated record incurs unnecessary print and postage costs. Verify the format against postal size, thickness, and weight bands before finalizing the design. Ensure the design sits within the band rather than at its edge. Proof with real records, including the challenging ones.
And record the returns afterward. A list that gets updated after every mailing becomes more cost-effective each time you use it.
