Mailing: Definition, Bedeutung & Beispiele im Direktmarketing

What is a Mailing? — Definition and Terminology

A mailing is a marketing communication sent to a defined recipient group. The term derives from "mail" (post) and serves as an umbrella term for both print mailings (advertising letters, postcards, selfmailers, catalogs sent by mail) and email mailings (marketing emails sent to recipient lists). The Gabler Business Encyclopedia defines direct mailing as "a promotional approach to a specific target group, selected based on an address database, through addressed advertising by mail."

The distinction from related terms: An advertising letter is a specific mailing format — the classic letter in an envelope with a cover letter and enclosures. Dialogpost is Deutsche Post's delivery service for marketing print mailings with reduced postage costs. A newsletter differs from email mailing in its regularity and informative character, while email mailings are sent irregularly and campaign-based. The history of mailing goes back far: Aaron Montgomery Ward sent the first general mail-order catalog in Chicago in 1872 — a price list with 163 products that laid the foundation for modern direct mail.

Print mailings are differentiated by addressing level: Fully addressed mailings are personally addressed to a specific recipient and achieve the highest response rates according to CMC 2021 (up to 3 percent). Partially addressed mailings target all residents of a household ("To the residents of...") and achieve lower response rates (up to 2.1 percent), but 30 percent lower cost per order. Unaddressed mailings are distributed by delivery area without address data.

Mailing Formats: From Advertising Letter to Catalog

The choice of mailing format has a measurable impact on campaign success. The CMC Dialogpost Study 2020 systematically compared the three most common formats for the first time based on 955,659 mailings from 41 online retailers.

The classic advertising letter in an envelope achieved a conversion rate of 5.7 percent — 25 percent more than the other two formats. Its ROAS was 15 percent higher than the postcard and 42 percent higher than the selfmailer. The reason: The sealed envelope creates curiosity and opening motivation, while the personal cover letter creates an individual approach.

The maxi postcard achieved a CVR of 4.6 percent with lower production costs. It is particularly suitable for tightly budgeted campaigns and quick messages — the recipient sees the marketing message immediately without opening. The selfmailer (without envelope, folded and sealed) also achieved 4.6 percent CVR but had the lowest ROAS of the three formats.

Beyond these, creative formats such as 3D mailings and pop-up mailings exist, which according to industry data achieve response rates up to five times higher than conventional flat formats. And the catalog remains a mailing format with special impact: According to a Splendid Research study commissioned by Deutsche Post, over 50 percent of catalog recipients subsequently visit the sender's website.

Mailing Production: From Concept to Delivery

The production of a print mailing follows a clear process chain: Concept (define target group, message, offer), Design (layout and copy), Data preparation (prepare addresses, personalize), Printing (digital or offset printing), Finishing (folding, enveloping, inserting), Sorting (by postal code according to Dialogpost requirements), and Delivery to Deutsche Post. Delivery typically occurs four days after submission.

A central production step is the lettershop — a service provider specialized in processing, assembling, and mailing postal communications. The lettershop handles printing, personalization, enveloping, postage, and postage-optimized sorting. Through Variable Data Printing (VDP), each individual printed piece can be individually personalized — with name, product image, voucher code, and personal salutation — without production interruption.

Costs consist of three components: Postage (Dialogpost from 0.36 EUR for postcards, from 0.38 EUR for standard letters with minimum 5,000 items; Dialogpost Easy from 500 pieces with surcharge), Printing and personalization (from approximately 0.12-0.25 EUR depending on format and volume), and Lettershop (enveloping and processing). Total costs per mailing typically range from 0.50 to 0.80 EUR. For comparison: A regular standard letter costs 0.95 EUR postage as of January 2025 — Dialogpost thus offers a significant cost advantage.

Success Factors: What Makes a Mailing Profitable

Four factors determine the profitability of a mailing: Target group selection, personalization, format, and timing.

Target group selection via RFM analysis (Recency, Frequency, Monetary Value) directs budget where the highest return occurs. The CMC Dialogpost Study 2020 proves: Customers with five or more previous orders achieve a three times higher conversion rate than one-time customers. For new customer mailings, Deutsche Post offers lookalike models: From 5,000 to 50,000 customer addresses, up to 500,000 new target group potentials are identified based on over 100 microgeographic characteristics.

Personalization is the strongest ROI lever. The RIT study by Romano and Broudy shows: Personalization with name and full-color image increases response by 135 percent; the combination of name, color, and data-based offer by up to 500 percent. According to the Lob State of Direct Mail Report 2025, 88 percent of marketing executives confirm that personalized direct mail improves response rates.

Timing significantly influences impact. CMC studies show a remarkable long-term effect: 47 percent of orders come in only from the fifth week after mailing (CMC 2025), with responses measurable up to 12 weeks (CMC 2021). According to JICMAIL, direct mail remains in households for an average of over 7 days and is viewed for a total of over 130 seconds. Repeated campaigns with multiple touchpoints increase ROI by 37 percent according to JICMAIL, with 2.5 times higher response rates.

Legal Framework: Print Mailing vs. Email Mailing

The crucial legal difference between print and email mailings concerns consent requirements. Print mailings are permissible under Art. 6(1)(f) GDPR (legitimate interest) without prior consent. Recital 47 of the GDPR explicitly states: "The processing of personal data for direct marketing purposes may be regarded as carried out for a legitimate interest." The Stuttgart District Court confirmed on February 25, 2022 (Case No. 17 O 807/21): Personalized mail advertising is permissible to new customers without consent and without an existing customer relationship.

Email mailings, however, require prior express consent (double opt-in) under German Unfair Competition Act Section 7(2)(3). The only exception: Section 7(3) UWG permits email advertising to existing customers for similar products if the email address was obtained during a purchase and the customer is informed of their right to object with each use.

For both mailing types, the right to object applies under Art. 21(2) GDPR: Recipients can object to the processing of their data for direct marketing at any time and without justification. For print mailings, each communication must include a reference to this right. The Robinson List of the DDV (German Direct Marketing Association) offers consumers an additional way to protect themselves against unwanted advertising. For data from third-party sources (e.g., purchased addresses), the information obligations under Art. 14 GDPR must be observed — the recipient must be informed about the data source.