Archives a segment (soft delete). The segment becomes hidden in the segment list UI but:

• Mailings that use this segment as a recipient filter continue to work
• Automation actions that reference this segment continue to work
• The segment can be unarchived later via the UI

There is one exception to the above: a segment that a published visual automation (Automation Builder) uses cannot be archived. The request is refused with 409, the segment stays active, and the response lists the automations that use it, which must be edited first.

Use archiving as a reversible alternative to permanent deletion.

The segment ID is globally unique — no newsletter context is needed.