Opt-Out

An opt-out occurs when a customer requests to be removed from your marketing communications. For SMS, this typically happens when a recipient replies with STOP (or UNSUBSCRIBE, CANCEL, END, or QUIT) to a marketing message. For email, it happens when a subscriber clicks the “Unsubscribe” link in an email or marks the message as spam. Both must be honored promptly — by law for SMS, and as a best practice for email.

Legal Requirements

Under the TCPA (US), SMS opt-outs must be honored within 24 hours, though best practice is to process them immediately and automatically. You must also send a confirmation message acknowledging the opt-out — and no further marketing messages after that point. For email, the CAN-SPAM Act (US) requires that opt-out requests be honored within 10 business days. GDPR (EU) requires immediate honoring of opt-out and erasure requests.

Opt-Out Rate as a Signal

A spike in opt-outs after a campaign is valuable feedback — something about that message (frequency, relevance, offer, timing) pushed customers to disengage permanently. Opt-out rates below 0.5% per send are generally healthy; higher than that warrants investigation. Regular spikes in opt-outs from specific segments often point to over-messaging those segments or misalignment between what they expected when they opted in and what they are receiving.

Suppression Lists

Opt-out management requires maintaining and respecting a suppression list — a record of every contact who has opted out of each type of communication. This list must be checked before every send, and opted-out contacts must never be re-added without new explicit consent. Most marketing platforms handle suppression list management automatically, but it is worth verifying that your setup is working correctly, especially after importing new contact lists.