Suppression list and deliverability

The Suppression List holds addresses that should never be emailed (unsubscribes, bounces, do-not-contact). Contacts on it are skipped by every campaign. Superadmins can also add do-not-contact rules by exact email, by company name, or by domain. A domain rule like "abc.com" blocks that whole domain; a rule starting with a dot, like ".gov.sg", blocks that domain and every subdomain (moe.gov.sg, iras.gov.sg, and so on), and applies to future contacts too. Keeping a clean list, warming up mailboxes, and stopping on replies all protect your sender reputation and deliverability.