If you have recently upgraded from an older version to 10.X or later and noticed that images in ticket update notification emails are replaced with the text
<<redacted by security settings>>
Then follow these steps to resolve the issue:
1. Navigate to the administration configuration pages.
2. Ensure that the "Include attachments into outgoing notifications" setting is enabled. This setting can be found under "Admin - Email." This setting now affects inline images too.
By enabling this setting, images should be included in your email notifications as before.