Bulk mail at a glance

1,000+

items to start receiving postage discounts

353MM X 250MM X 25MM

Maximum Large Letter dimensions

750G

Maximum Large Letter weight

3-4 DAY

turnaround to produce and dispatch bulk mail

What are bulk mail services and how can The Mailing People help?

A bulk mailing campaign is the perfect way to send out large quantities of letters quickly, effortlessly and at minimum cost. Bulk mail services typically require runs of at least 1,000 items, with larger campaigns extending into the tens of thousands. According to JICMAIL, direct mail has a lifespan of almost eight days once delivered and is interacted with an average of 4.5 times. Return on investment for these campaigns is also strong, ranging from £2 for every £1 spent on partially addressed mail, up to £11.50 for warm direct mail campaigns that target existing customers.

It’s easy to see why charities and businesses use a bulk mail service to deliver fundraising campaigns, donor packs, vouchers and mini product catalogues. It’s a great way to connect and re-connect, filling the gaps left by your digital campaigns and helping to drive recipients online.

Because the size, weight and format of each piece determine the postage rate it qualifies for, we advise on the most cost-effective specification before anything is printed. From there, we prepare and clean your data, manage production and delivery from start to finish, then secure every postage discount you’re eligible for.

8 DAYS

Lifespan of direct mail once delivered

4.5X

Average number of interactions per item

£11.50

Return for every £1 spent on warm direct mail to existing customers

Source: JICMAIL Q1 2026

How bulk mailing works, step by step

Our mass mailing service sees every bulk campaign follow a clear managed path, from the day we receive your data to the moment it’s released to post. Many of the bulk mailing service savings and efficiencies we offer come from how your mailing is prepared at scale.

To help you better understand how to send letters in bulk, here’s how our typical process works:

1

Secure data ingestion

You upload your recipient data through our secure portal and supply your artwork. We are an ISO 27001 certified business, so you can be confident that your data is treated confidentially and handled to a recognised information security standard.

2

Data processing

Your data can be checked and cleansed to improve accuracy, which keeps wasted print and postage to a minimum. It is then formatted and sorted for both personalisation and postage, structuring the mailing so it qualifies for the best available discounts.

3

Personalisation and print:

Even on the largest runs, variable data printing can be used to tailor every item to its recipient, from names and addresses to images and copy, all in full colour. Your job is then printed on digital or litho presses, depending on which will be best suited to your volume and quality needs.

4

Fulfilment and enclosing

We finish and assemble your mailing to the agreed specification, then enclose or wrap it on automated lines that handle everything from A6 to A4 and process up to 10,000 envelopes an hour.

5

Postage

Because we prepare and sort your mailing to meet carrier requirements such as MailMark®, you’ll often qualify for discounted postage rates. We can advise on which discounts you’re eligible for and take steps to meet all necessary requirements. Finally, we then release your campaign to post on the agreed date.

Bulk mail postage and discounts

Postage often accounts for at least half the total cost of any direct mail campaign, so securing every available discount makes a real difference. Depending on what you want to send out, you may qualify for reduced bulk mail postage rates such as business mail, advertising mail or publishing mail. Where your sorted mail is eligible, using machine-readable barcodes that meet Royal Mail’s automated standards can unlock further MailMark savings.

These discounts depend on volume. To qualify for sorted bulk mail rates you need a minimum of 1,000 Large Letter items or 4,000 Standard Letter items. Pricing becomes most cost-effective once you pass 4,000. There’s no upper limit, so larger mailings can save even more. For Large Letters, each item must also fall within the qualifying limits of 353mm x 250mm x 25mm and weigh no more than 750g. For Standard Letter mailings, the limits are 240mm x 165mm x 5mm and 100g.

To take advantage, your data must be clean, accurate and correctly formatted, then sorted to meet carrier requirements. We handle this preparation for you, advising on the most cost-effective format and applying every discount you qualify for across all the main delivery providers.

Standard Letter

240 x 165 x 5mm

Up to 100g. Sorted rates from 4,000 items.

Large Letter

353 x 250 x 25mm

Up to 750g. Sorted rates from 1,000 items.

Find out how The Mailing People can help you obtain the best postage cost for your next bulk mailing campaign.

Fulfilment and enclosing options

Once your items are printed, they need to be collated, sealed and made ready for posting. As a comprehensive, end-to-end mailing house, we offer a full range of high-volume fulfilment methods to suit different formats, volumes and budgets and can advise on the most efficient, cost-effective method for you. Mail fulfilment options to consider for high-volume bulk mail include:

01

Automated folding and finishing

High-speed lines fold, score, staple, glue, tab and drill printed items in large runs, keeping quality consistent and per-item costs low.

02

Envelope enclosing

Our automated Buhrs machines insert single or multiple pieces into DL, C5 or C4 envelopes at a rate of up to 10,000 an hour, handling mailings from A6 to A4. That adds up to 160,000 envelopes a day.

03

Polywrapping or paper wrapping

A clear film or paper outer seals magazines, catalogues and multi-piece mailings, protecting the contents in transit and letting several items travel together.

04

Personalised fulfilment

On high-volume litho runs, spot sealing can be used to make materials suitable for digital overprinting. This combines the economies of scale for runs of more than 10,000 items with the personalisation capabilities of digital print. Wrapped mailings can also include personalised carrier sheets, printed in full colour front and back.

Bulk mail personalisation at scale

Sending thousands of letters doesn’t mean abandoning the personal touch. Even on the biggest campaigns, variable data printing lets you tailor each item to the person receiving it, so even if you post bulk mail items by the thousand, they still read as though written for one individual.

The scope goes well beyond a name at the top. Almost any element can change from one item to the next, including the address, greeting, imagery, body copy and specific offers, all driven by the data on your list. A single run can therefore speak differently to each segment of your audience, produced together in one pass.

This stays cost-effective as volumes climb. Even runs of more than 10,000 items can be tailored to each recipient without a jump in unit cost, while outer envelopes can be printed in full colour to make a personal impression before the mail is opened.

Data cleansing for bulk mail

When you mail in bulk, errors, duplicates and out-of-date addresses are inevitable, but they are avoidable. ONS figures show millions of people move home across England and Wales every year, so any list left unchecked steadily fills with addresses that no longer reach anyone. Because every duplicate or undeliverable item is still printed, fulfilled and posted, these expenses impact your campaign budget for no benefit.

We can check your mailing list against recognised quality criteria to remove duplicates, gone-aways, invalid postcodes, deceased records and Mailing Preference Service registrations before your mailing is produced. We can even enrich your bulk mailing list by adding in traceable contacts that have moved. For charities, alumni groups and organisations keen to retain contact with donors and clients, this is especially important.

Frequently Asked Questions