Commercial email typically needs a clear, working way to opt out. When someone unsubscribes, the sender must record the request and stop sending to that address, normally promptly and across all related lists.
Why it matters
Honoring opt-outs is a legal requirement in many places and a basic matter of respect. It also protects deliverability, because people who cannot unsubscribe often mark messages as spam instead.
Common pitfalls and tips
Keep one shared suppression list across tools and teammates. Re-importing an old list without checking it against suppressions is a common way opted-out contacts get emailed again.
Example
A prospect clicks the unsubscribe link in a sales email. The address is added to a suppression list used by every rep and tool, so no future campaign reaches it.
How Leadvaro relates: Our guidance on responsible outreach is in the GDPR page.