The Email for Trello Power-Up is made by SendBoard and allows you to connect your inbox to Trello so that you can send and receive emails directly from your board.

Each SendBoard card has a reference number indicated at the top of the card.

This reference number can be included in your auto replies or saved responses by using the following variable: {%referenceNumber%}. It can be used as a ticket reference when shared with clients for example. The reference number can also be used to forward emails to an existing Trello card by adding it in the subject of the email. Read more about that here.

Trello's Butler Automation does not have direct access to SendBoard variables, but it possible to extract the reference number to use in automation rules.

When the first email is sent/received on a card, the reference number is set in the comment text. You could use Butler pattern matching rules to extract the reference number from the comment and use it in your automation rules and workflow. For example, append it to the card title or save it to a custom field.

Here are a few examples of extracting the reference number and using it in Trello Automation rules:

Create a Trello Automation rule to extract the reference number from the comment, and rename the card to include the reference number.

Your automation rule would look like this:

when a comment containing "Reference: **[{?}]" is posted to a card with a name not containing "REF", rename the card to "{cardname} - REF: {wildcard1}"

The rule above will prevent the reference number from being added again every time a new email is received on the card. It will only add it if there is no reference number in the card name.

You will first need to create a custom field to hold the reference number. For example "REF".

Next, you can create a rule to extract the reference from the Trello comment and save it to the custom field. Once the Reference number is saved in the Custom Field, it can be used in other areas of your workflow, with other Power-Ups or even be configured to display on the card when you are in board view.

Your automation rule would look like this:

when a comment containing "Reference: **[{?}]" is posted to a card with custom field "REF" cleared, set custom field "REF" to "{wildcard1}"

The rule above will prevent the reference number from being added again every time a new email is received. It will only add it if there is no reference number saved to the custom field "REF".