> For the complete documentation index, see [llms.txt](https://docs.emaildelivery.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.emaildelivery.com/docs/transactional/transactional-tags.md).
# Transactional tags
{% hint style="warning" %}
**If you use a transactional template that has already been tagged, additional tags used in the header or API request are discarded.**
{% endhint %}
Create transactional mail streams with their own analytics by including a tag with the message.
Messages sent without a tag will be grouped together as 'untagged' on the transactional dashboard.
{% hint style="info" %}
**Transactional messages can be tagged via SMTP Relay, API, or Template methods.**
{% endhint %}
* SMTP Relay can use the header X-Transactional-Tag:
```
X-Transactional-Tag: signup
```
* API can use the tag parameter:
```
"tag": "signup",
```
* SMTP Relay can use the header X-Transactional-Template:
```
X-Transactional-Template: MsmsEaZZDxYyBJyVXXwA2A
```
* API can use the template parameter:
```
"template": "MsmsEaZZDxYyBJyVXXwA2A",
```
{% hint style="info" %}
**Adding a Message Tag to a transactional template will cause all messages that use this template to be tagged automatically.**
{% endhint %}