By default, when users receive email notifications about their tickets, the From: name on the email is the Agent's name, this is to make the support feel more personal. However, if you’d rather just have the email sent from a general name, i.e., "Acme Support", you can change this.

To do so, you need to edit two default Triggers that email the User when an Agent replies (‘Send User new reply from Agent’ and ‘Send User new Ticket by Agent’).

In Admin > Business Rules > Triggers > New Reply Triggers, go to the Send user new reply from agent trigger, and click on the pencil on the right.

Change the From Name: field from "Name of the person who initiated the action" to use your Helpdesk Name or a custom name of your choice.

Then repeat these steps for the Trigger "Send User new ticket by agent" trigger in Admin > Business Rules > Triggers > New Reply Triggers.

You can use variables in a custom name. For example, if you want the From: name to include the name of the department the ticket is in, you could use this as the custom name:

Acme {{ticket.department.title}} Department

Another useful variable that can be used in 'Custom Name'  if you would like to show the agent name, but also preface this with some set text is:

{{ ticket.agent.display_name }}

You should also do the same for the "Send User new ticket by agent" trigger in Admin > Business Rules > Triggers > New Reply Triggers.