Why does the Drumkit smart sidebar reset when I open an attachment in Outlook?

Last updated: September 10, 2026

Short answer: This is how Microsoft Outlook handles add-ins, not a Drumkit bug. When you open an attachment preview, Outlook restarts the Drumkit sidebar from scratch, which clears anything you've typed but not yet submitted. Below are a few habits that avoid it entirely.

What's happening

Outlook runs every add-in, Drumkit included, inside a secure sandbox that's tied to whichever email you currently have selected. When Outlook switches what's "active" in that window, it shuts the add-in down and starts it again fresh.

Opening an attachment preview is one of those switches. So is hitting Reply or Forward inline, or clicking to a different message. In each case Outlook reloads Drumkit, and any in-progress entries in the Builder sidebar are cleared.

This applies to every Outlook add-in, not just Drumkit, and Microsoft doesn't currently give add-ins a way to opt out of it.

How to avoid losing your work

1. Review attachments before you start building. Open whatever you need first, such as the rate confirmation, the load tender, or the spreadsheet, and read it. Then open Drumkit and build the load in one pass. This is the single most reliable habit.

2. Open attachments in their own window instead of previewing them. Rather than single-clicking to preview inside the reading pane, use the attachment's dropdown arrow and choose Open in New Window, or Save As and open it from your desktop. A separate window doesn't change Outlook's active item, so the Drumkit sidebar keeps running.

3. Pop the email out first. Double-click the email to open it in its own window, then open Drumkit from there. You'll have a dedicated window for building, and you can browse your inbox in the main window without disturbing it.

4. Use a second monitor or a split screen. Keep the attachment open on one side and Drumkit on the other.

5. Submit the load, then edit. If you already have enough to create the load, build it and make corrections in your TMS afterward rather than holding a half-finished form open.

Good to know

  • Drumkit's AI has usually already read the email's attachments when it generates a Builder suggestion, so in most cases you don't need to open the attachment to fill in the form.

  • Pinning the Drumkit sidebar helps it stay open as you move between emails, but it does not prevent the reload described above.