Opt-in / Opt-out
Opt-in: prior consent before contact. Opt-out: the right to refuse afterwards. Their regime depends on channel and context.
Opt-in requires explicit agreement before any send (the general B2C rule). Opt-out allows contacting and then offering an easy way to unsubscribe (often accepted in B2B on a legitimate-interest basis).
Whatever the regime, every message must include a clear unsubscribe mechanism and honor it immediately. Maintaining a suppression list is an obligation as much as a deliverability best practice.
Related terms
To go further, read our B2B data enrichment guide or try the free email verifier.
From theory to practice
Listar enriches and verifies professional emails and phones with a waterfall across 30+ sources. Import a list, get reachable contact details.
Try Listar