Backspace inside draft composer archives the thread in v1.20.0

Bug Reports
1

Description

In Mailspring 1.20.0 (snap revision 600), pressing Backspace while the cursor is inside the body editor of a draft/composer window archives the entire thread instead of deleting a character. A toast appears: “Moved to Archive”.

Effectively it makes composing or replying to messages impossible. Any other keystroke in the body also appears to leak through to the global keymap (e.g. e, letters that are bound in the Gmail template) — but Backspace is the most disruptive.

Happens on every account (tested with 8 different IMAP accounts: Gmail, Netsons/cPanel IMAP, custom IMAP) and every draft, new or existing. Emptying keymap.json to {} and setting keymapTemplate to “” in config.json does NOT fix it — which suggests these bindings are hardcoded, not coming from the template files.

Reverting the snap to revision 597 (v1.19.1) fully resolves the issue: sudo snap revert mailspring.

To Reproduce

Steps to reproduce the behavior:

  1. Open Mailspring 1.20.0
  2. Click on any existing draft, or hit Compose to create a new message
  3. Put the cursor inside the body editor
  4. Type a few characters, then press Backspace
  5. The thread is archived instead of the last character being deleted

Expected Behavior

Backspace inside a contenteditable composer body should delete the preceding character. Global keyboard shortcuts (archive, reply, etc.) should NOT fire while focus
is inside the composer editor.

Screenshots

N/A — trivially reproducible with any draft.

Setup

  • OS and Version: Ubuntu 25.10, kernel 6.17.0-22-generic
  • Installation Method: Snap (latest/stable channel)
  • Mailspring Version: 1.20.0 (snap revision 600) — broken. 1.19.1 (snap revision 597) — works correctly.

Additional Context

  • Keyboard layout: Italian (it), IBus input method active.
  • Language setting in Mailspring: Italian (intl.language: it).
  • Template: keymapTemplate: “Gmail” (default).
  • Disabled packages (from config.json): message-view-on-github, personal-level-indicators, phishing-detection, nylas-private-salesforce, github-contact-card,
    keybase, composer-markdown, composer-scheduler, composer-mail-merge, send-and-archive, main-calendar.
  • The snap package 600 was published around 2026-04-20 and auto-refreshed on my machine at 10:32 UTC — the regression appeared immediately after the refresh.
  • Workaround until a fix is released: sudo snap refresh --hold=forever mailspring to pin to 1.19.1.
2

I can confirm that behaviour, and it makes the app unusable for writing emails right now, unfortunately.

OS and Version: macOS (26.4.1)
Mailspring version 1.20.0

3

Same here ! And there’s other glitches when composing a reply for example. Space bar immediately close the draft, backspace archive it … I’m back to v1.18.0 for now
OS and Version : Ubuntu 22.04.5 LTS
Mailspring v1.20.0

4

The same issue is for me on my Mac. No idea how to revert to the previous version, so I’m screwed for now. I rely solely on Mailspring for my e-mail, including my business e-mail.

Besides the backspace not working, also space isn’t working. It sort of leaves the e-mail. Totally unusable. For now I type my text in a text editor and then paste it in my e-mail.

For me this is an urgent and priority 1 bug.

5

Same problem on v1.20.0 on windows. Backspace archives the post, spacebar scrolls down/types nothing. Basically can’t type. Reverting to V1.19.1 fixed the issue.

6

Same here. Every key connected to the shortcut doesn’t appear in the reply window, and performs the actual actions with this given email.

7

Possibly related?: When I hit the Delete button (or Backspace button) for a selected email in the Inbox, that email is archived rather than deleted. This issue first appeared for me a couple of releases ago. I’m currently running v1.20.1 under Manjaro Linux.