Lob's website experience is not optimized for Internet Explorer.
Please choose another browser.

Arrow Up to go to top of page
Most Common Direct Mail Terms
May 16, 2022

Most Common Direct Mail Terms

Author Avatar
Guest Author

Just as in any other industry, direct mail marketing is filled with acronyms and jargon. Savvy marketers speak fluently in marketing terms like CTRs, CPAs, engagement rates, open rates, and so on. In the email marketing world, email addresses are "scrubbed" to remove fake emails and deleted accounts. Similarly, address verification allows physical mailers to check the accuracy of the addresses on their list, fix mistakes, and avoid undeliverable mail.

As a smart marketer or business owner, you may be able to interpret many of these terms intuitively, but others may be completely foreign. By learning direct mail lingo, you can better use this powerful marketing channel to reach new customers, reduce churn, and build a loyal customer base that sticks around. If you understand direct mail terms, you can prepare for campaigns better in the beginning and measure results more clearly at the end.

Direct mail terms every marketer should know

Most Common Direct Mail Terms image 2
Lob's address standardization

Address standardization

This direct mail service feature helps business owners make sure addresses adhere to the proper postal formats. It also autocorrects typos and errors. Having all addresses on your list standardized is good 'data hygiene,' and it reduces the chance of a mailing mistake. In Lob, you can access this feature by using print/mail address auto verify, which doesn't require a separate subscription to the Address Verification API service.

Address verification

Postal address verification allows senders to make sure their mail will be deliverable and that location is valid (addresses are valid if they are CASS-certified). This process ensures the highest possible ROI while helping mailers maintain their database's integrity over time. Lob's software provides address verification APIs, which verify each recipient's address and ensure proper formatting. Any address can be verified in a matter of seconds, and a Lob confidence score is given (e.g., 100% likelihood of being deliverable). Learn more

Analytics dashboard

An analytics dashboard lets users view both delivery and mail speed on a segment by segment basis. Direct mail platform users can filter and sort data using metadata tags. As with any analytics tool, your direct mail dashboard will show you how your campaigns are doing in real-time. This helps you measure campaign results, track ROI more closely, and learn how to spruce up your next campaign.


It is best practice to group similar materials when mailing out items. Batching allows the postal service to operate more efficiently by grouping similar materials into single packages. This ensures all the right materials are pieced together and sent to your customers in one piece. It contributes to a simpler mailing process and ensures a high-quality customer experience.

CASS certification

CASS stands for Coding Accuracy Support System. This certification is given to an address once it is verified as deliverable (address standardization must take place first). Once an address is CAAS certified, mailers can be sure that the zip code, carrier route, and 5-digit coding are correct. The USPS assigns delivery point codes to specific mailboxes, which are also checked through the CASS certification process. By catching these and other errors such as typos, mailers can make sure their mailing list is clean and accurate before each campaign goes out.

Cancellation window

When mistakes happen or a mailer changes their mind about the materials they were preparing to send out, canceling is the best option. Lob's cancellation policy offers mailers the opportunity to halt the production of a mail campaign free of charge via the API or Dashboard.

Delivery point

A delivery point is just what it sounds like - a specific place in which mail can be delivered. A delivery point may be a resident's personal mailbox, a business mailslot, or a PO Box. A delivery point code is simply the resident's full 9-digit zip code plus the last two numbers of their address.

Intelligent Mail barcode (IMb)

Intelligent Mail Barcode (IMb) is a US code that helps mailers track letters and flats more efficiently. A single barcode is used to participate in multiple postal service programs simultaneously. IMb also increases the mailer's ability to track individual mailpieces and provides greater visibility by letting mailers see the entire contents of each letter or flat. Businesses can get barcodes printed on documents or in envelope windows to easily track what is sent out.

First-Class Mail (FC mail)

When a message needs to be delivered with lightning speed, you can count on First-Class Mail (FC mail). One of the more well-known direct mail terms on this list, FC mail simply refers to mail sent quickly. This may be a postcard, large envelope, letter, or small package—anything less than 13 ounces. If more than 13 ounces, it becomes priority mail. When using Lob, businesses can expect first-class mail to be delivered 4-6 business days from an API request. By comparison, standard mail takes about 7-21 business days.


An indicia is a marking that appears on mail in place of a stamp. Indicias indicate that postage has already been paid, and thus manually stamping each envelope isn't necessary. This saves time and effort and gets large-scale mailings out faster.

In-transit mail tracking

Looking for a surefire way to do direct mail tracking better? There's nothing more reassuring than knowing every mailer in your campaign has reached its intended audience. Lob offers direct mail tracking in real-time, which means you can keep tabs on your mail as it progresses to its destination. In Lob, in-transit mail tracking includes an auditable record and automated webhook.

National Change of Address (NCOA)

When residents move away, they can submit a change of address form to the US Postal Service. Through the NCOALink, this information can be made available to mailers, who then have an opportunity to scan and update their mailing list automatically. This dataset includes millions of individuals, families, and businesses that have moved within the past 18-48 months, depending on the license.

Nixie Undeliverable mail

When mail is undeliverable, it is marked with a yellow label. A code will be printed on the label to indicate the reasons why the mail couldn't be delivered. Most often, the reason is a change of address, missing or incorrect address information, a vacant location, or a change of address has expired (COAs last for one year). Nixies are another resource mailers can use to keep their address list up-to-date. When mail is undeliverable, mailers must update or remove the address in question.

Personable Identifiable Information (PII)

PII refers to any personal information that is attached to an individual. Things like social security numbers, driver’s license numbers, or personal records. PIIs are often relevant to mailers in the healthcare and financial service industries who send clients' private documents via mail.

Priority mail queuing

When you need something sent fast, priority mail queuing is your jam. A big part of direct mail automation is moving campaigns more quickly (and with fewer steps required). Once you get the hang of it, priority mail queuing can be a major asset for your direct mail marketing strategy. In Lob's platform, this is the direct mail term for the highest priority mail production.


Self-mailers are simply mail pieces that arrive outside of an envelope. A postcard, a catalog, a booklet, or a sealed piece of paper could all be considered self-mailers in their own right. For marketers, self-mailers provide a minimalist template for reaching customers and raising ROI without much planning and effort. They're inexpensive, easy to create, and likely to grab your customer's attention when they open their mailbox.


In 1983, the USPS added 4 additional numbers to further specify the standard 5-digit zip code. The first 5 numbers refer to the wider area, while the next 4 numbers refer to the specific area where the address is located (eg. within a block or two of the destination).

Give your direct mail ROI a boost

You may have a few minutes to browse through common direct mail terms, but let's face it – you probably have more important things to do, and so does your team. Direct mail marketing tasks can easily take more time than they're worth. That's why we simplify direct mail and address verification, giving companies more flexibility, visibility, and accuracy of offline communications and data.

Recommended resource: Direct mail FAQs

Schedule a demo to learn how to effortlessly track direct mail using Lob’s Print & Mail and Address Verification APIs.

Continue Reading