Create a Postbox on Postworks portal

A Postbox is required to send letters using Postworks. You can set up different Postboxes for different teams, locations or workflows - and assign user permissions and preferences for each.

1. Creating a new Postbox

From the main menu on the left, select Send:


20.0 Create a Postbox on Postworks portal

Click on Create new:


20 Create a Postbox on Postworks portal

2. Make sure Postbox is selected:

Make sure that Postbox is selected (toggle should be red and facing towards Postbox)


20.01 Create a Postbox on Postworks portal

  • Ignore Teambox for now unless multiple users will use it

Postbox names must be unique within your account.

3. Enter the Postbox name

  • Pick something clear and specific (e.g. “Finance - Leeds”, “Legal Returns”)

4. Choose the letter Type

No split, they're separate letters - choose that if your document contains only one letter.

Split by page - choose if your PDF contains multiple recipients.


  • If you are uploading a mail merge and each letter is made of a fixed number of pages, choose this option. 
  • We'll identify that each letter is going to a new recipient based on how many pages you choose the letters are split by.

E.g.: If you have a 100 paged PDF file containing 2 paged letters, enter 2 on the Page box to split the letter by 2 pages.

Split by keyword - if your PDF contains multiple recipients with varying page count.

  • If you are uploading a file that has a varying number of pages going to each recipient, this split type will identify each letter by searching for a keyword.
  • The keyword must be on the first page of every letter and in the same position each time. Be aware keywords are case-sensitive.

It is recommended to use Split by Keyword only for letters that are system-generated.

If the keyword is not consistently positioned in each letter, there is a possibility that the letters may not be split accurately.

  1. Select Show us where your keyword will be.

24 Create a Postbox on Postworks portal

2. Click on Change PDF and select the PDF that includes your keyword.

25 Create a Postbox on Postworks portal

26 Create a Postbox on Postworks portal

3. Select the Watchzone (red box) by drawing it out - our system will look for the keyword in this area.

  • The watchzone should be big enough to ensure the keyword is captured each time. It doesn't matter if there is other data within the watchzone area.
  • Examples of common keywords that can be used include "Our ref," "Page 1," "Date," and "Dear."
  • In the example below, we've chosen the word 'INVOICE' as a keyword.

27 Create a Postbox on Postworks portal-1

4. Click on Submit.

5. Ink:

Choose Black or Colour based on the ink you want the letters to be printed with.

6. Posted:

Choose between 1st Class or 2nd Class.

7. Advanced Settings:

Do you want these documents printed:

  • Single-sided printing - prints only on one side of the paper. This often essential, for example when sending a form that has to be filled in.
  • Double-sided printing - prints on both sides of the paper. It is more cost-effective and saves trees as it uses less paper - this is selected as default.
    •  PBID (Advanced Users Only)

A PBID (or Postbox ID) is a code that activates a Workflow™, which is an automated routine that regularly performs tasks with your documents. These tasks may include adding letterheads, specific attachments and setting default print settings.

Workflows™ can also be triggered based on content, sender, filename or PDF metadata.

    • Display Add attachments on upload

When you upload a PDF, you will be prompted to add attachments if it's enabled.

      • Add Digital Reply Envelopes

      When you activate this feature, a digital reply envelope will be automatically added to all items uploaded to your Postbox. For more information on what a digital reply envelope is, please refer to this article.

      • Make this my default Postbox
      If you are using PostboxPrint™, this postbox will be used as default when uploading items.

    8. Select Save to store your preferences for future use.

    Now, let's Post a letter.