---
title: "Add Categories To Emails"
slug: "add-categories-to-emails"
updated: 2025-09-02T19:26:11Z
published: 2025-09-02T19:26:11Z
canonical: "documentation.decisions.com/add-categories-to-emails"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://documentation.decisions.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Add Categories To Emails

| Step Details |
| --- |
| **Introduced in Version** | 9.10.0 |
| **Last Modified in Version** | 9.10.0 |
| **Location** | Integration > Exchange Web Services |

The **Add Categories To Emails** step allows users to add categories to emails inside the Flow Designer. The Step takes in a list of Email IDs and a list of Categories to add to those emails.

### Prerequisites

- This step requires the [Exchange Web Services module](https://documentation.decisions.com/docs/microsoft365-exchange) to be [installed](https://documentation.decisions.com/docs/installing-modules-decisions) before it will be available in the toolbox.
- A [dependency](https://documentation.decisions.com/docs/project-dependencies) must be created after installing the module in order for the Steps to be properly used.

---

## Properties

#### Inputs

| Property | Description | Data Type |
| --- | --- | --- |
| Categories | The string list of Categories to be added to the emails. | List of String |
| Exchange Server | The server and authentication to use. | ExchangeServerDefinition |
| Ids | The string list of email IDs that categories will be added to. | List of String |

![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1751993807309.png)

---

## Common Errors

### Value Cannot Be Null

If a value was not inputted prior to running the step, the step will cause an error.

To correct this, ensure all input fields are properly filled out.

#### Error Message:

```csharp
DecisionsFramework.Design.Flow.ErrorRunningFlowStep: Error running step Add Categories To Emails 1[AddCategoriesToEmails] in flow [Step Library Flow]: Exception invoking method AddCategoriesToEmails on class ExchangeEmailSteps
 ---> DecisionsFramework.LoggedException: Exception invoking method AddCategoriesToEmails on class ExchangeEmailSteps
 ---> System.ArgumentNullException: Value cannot be null. (Parameter 'value')
 at System.Enum.Parse(Type enumType, String value)
 at Decisions.Exchange.Utilities.GetExchangeService(ExchangeServerDefinition def)
 at Decisions.Exchange.ExchangeEmailSteps.AddCategoriesToEmails(ExchangeServerDefinition ExchangeServer, String[] Ids, String[] Categories)
 at InvokeStub_ExchangeEmailSteps.AddCategoriesToEmails(Object, Span`1)
 at System.Reflection.MethodBaseInvoker.InvokeWithFewArgs(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   --- End of inner exception stack trace --- at DecisionsFramework.Design.Flow.StepImplementations.InvokeMethodStep.Run(StepStartData data)
 at DecisionsFramework.Design.Flow.FlowStep.RunStepInternal(String flowTrackingID, String stepTrackingID, KeyValuePairDataStructure[] stepRunDataValues, AbstractFlowTrackingData trackingData)
 at DecisionsFramework.Design.Flow.FlowStep.Start(String flowTrackingID, String stepTrackingID, FlowStateData data, AbstractFlowTrackingData trackingData, RunningStepData currentStepData)
   --- End of inner exception stack trace ---
```

---

## Step Changes

| Description | Version | Date | Developer Task |
| --- | --- | --- | --- |
| Add Categories To Emails step added to module. | [9.10](https://documentation.decisions.com/v99/docs/version-910x-release-notes) | May 2025 | [DT-044217] |

---

Related InformationRelated Articles:  
  
[Exchange Web Services Module](https://documentation.decisions.com/docs/microsoft365-exchange)