Junk Sender: send everything from a sender to Junk with one click

theoryshaw · September 10, 2026, 5:14pm

Mailspring’s mail rules can already send a sender’s mail to Junk, but setting one up means opening Preferences and building the rule by hand. Junk Sender does it in one click from the email itself.

Select an email and a funnel button appears in the toolbar. Clicking it:

creates a mail rule, From equals sender → Move Message to folder: Junk, so their future mail goes straight to Junk
moves the email you selected, plus every conversation in your Inbox with a message from that sender, to Junk

Hover over the button to see exactly which address it will filter. If a sender already has a rule, the button is still there: clicking it clears out anything of theirs still in your Inbox, without creating a second rule.

[screenshot]

The rules are ordinary Mailspring mail rules, so you can edit or delete them under Preferences → Mail Rules. If you click it by mistake, use Undo to move the emails back, and delete the rule there.

Install

Download it from GitHub: GitHub - OpeningDesign/mailspring-junk-sender: Mailspring plugin: a toolbar button that sends all mail from a sender to Junk, including what's already in the Inbox · GitHub (Code → Download ZIP), and unzip it.
In Mailspring, choose Developer → Install a Plugin… and select the unzipped folder.

It’s plain JavaScript, so there’s no build step, and it doesn’t modify Mailspring itself. To update, install the new version the same way and restart Mailspring.

Good to know

IMAP accounts only. The button is hidden on Gmail accounts, because Mailspring’s rule editor only offers label actions there. Gmail’s own “Block sender” does the same job on Google’s servers.
Rules run inside Mailspring, not on your mail server. A filtered sender’s mail can still show up in your Inbox on your phone until Mailspring has synced it.
Existing mail is found through Mailspring’s search index, so conversations it hasn’t indexed yet won’t be moved.

I’ve tested it on Windows. Bug reports and suggestions are welcome here or as GitHub issues.