Sections are specific types of content that you can add to a TMail. They are useful when you expect revisions to this content.

Sections are similar to attachments in some ways and differ in some other (crucial) ways. The easiest way to think of them is as updateable attachments.

Similarities to attachments

1. They are intrinsically bound to the TMail thread. They can only be changed in the context of a Response.
2. Whoever has access to the thread has access to the Sections (if any). So, unlike a link to a shared document, there is never any risk of ‘losing access’ to a Section.
3. Multiple Sections can be changed in a single response.
4. Just like sending a revised attachment does not modify an earlier version, so to updating and deleting Sections has no impact on earlier versions. This is referred to as append-only updates.
5. The ‘release’ of Section changes is under the control of the user.

Differences from attachments

1. Attachments are always files. Sections come in multiple types including File, Text, Grid and Form. Additional Section types will be added over time.
2. Text, Grid and Form Sections can be edited right inside the application.
3. They are linearly versioned.
4. You can see the difference between versions of Sections.
5. There is no ambiguity about the latest version.
6. Sections can not only be added but also updated or deleted
7. They can be ‘branched‘ and ‘merged‘ back.
8. They can be uniquely referred to via a Section URL. Even a particular Section version can be uniquely referred to via a Section Version URL.
9. Every Section has a title. This title refers to all versions of the Section.

In a sense Sections let you have your cake and eat it too. They are inline like attachments but avoid the version nightmare of attachments.

Through their diff capability they allow any user to see how the TMail thread got to its current state. In other words they let users see the journey not just the destination.

Sections are the basis of representing the state of a thread. They are also key to the concept of goal-oriented discussions as well as the representation of Process state. As such they are a critical element of what makes TMail different.

Note that TMail also supports traditional attachments which are associated with a Response changeset.