Within Teamwork.com, you can quickly add a new message from any area of your site via the quick add menu.
Select + Quick add from Teamwork.com's main navigation menu. In the quick add pop-out menu, click ... More, then select Message.
When using the quick add option in a site-level area, you'll first need to choose a project to add the message to. If you use the quick add message option while in a project, the message will default to that project — you can change the project during creation.
Use the editor to create your message. Click Post Message to add it to the project.
For more information, see: Using the Quick Add Menu