My recipients see "{DISARMED}" in the subject line of emails I send from Mailspring

We are phasing out Zendesk. Please see Discourse instead: https://community.getmailspring.com/t/disarmed-in-subject-line/285

The text "{DISARMED}" is added to email subject lines by Norton Antivirus. The Norton software is running on your recipients computer (not your computer) and modifying emails as they receive them in Outlook.

The information here for Thunderbird also applies to Mailspring: https://support.mozilla.org/en-US/questions/1162415

Norton Antivirus adds the "DISARMED" text to the email subject line whenever the incoming email contains read receipts or link tracking. To avoid having {DISARMED} appear on your emails when sending from Mailspring to a user that runs Norton Antivirus, turn off read receipts and link tracking in the Mailspring composer by clicking the blue "eye" and "link" icons at the bottom of the window.

Ben