Email Suppression List
Also known as: Suppression List, Do Not Email List
An email suppression list is the canonical record of addresses that must not receive outbound mail from the sender. Every cold-outbound platform maintains one. The list includes unsubscribes, hard bounces, complaint reporters, role accounts (info@, support@, etc.), and known competitors or partners.
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The suppression list is the operational layer of compliance and deliverability hygiene. Sending to suppressed addresses is what causes most legal exposure (under CAN-SPAM, GDPR, CASL) and most reputation damage.
What to suppress
- Unsubscribes: legally required. CAN-SPAM 10 business days, GDPR immediate.
- Hard bounces: deliverability hygiene. Sustained hard-bounce sending degrades reputation.
- Complaint reporters: anyone who marked the sender as spam. Same as unsubscribe operationally.
- Role accounts: info@, support@, sales@, admin@, etc. typically catch-alls or shared; low engagement, high spam-complaint risk.
- Out-of-office indicators: if an address sends OOO with role-change language, suppress until updated.
- Disposable/spam-trap domains: maildrop.cc, mailinator.com, tempmail, and known spam-trap-heavy domains.
- Competitor and partner addresses: business policy, not deliverability, but standard practice.
How to maintain
- One canonical suppression source; all sending tools query it before send
- Append-only (never delete a suppressed address)
- Honor across sender-domain changes (suppression follows the sender, not the domain)
- Audit quarterly for stale or wrongly-suppressed entries
Track real engagement, not Apple MPP noise.
Start Free TrialFrequently asked questions
Where does the suppression list live?+
Most cold-outbound platforms (Saleshandy, Outreach.io, Salesloft, HubSpot Sales Hub) maintain their own suppression list. The best practice is one canonical source that every sending tool queries; harder than it sounds in practice.
Does Outsolvi maintain a suppression list?+
Yes, for the mail Outsolvi sends. Settings > Blocked lists the addresses Outsolvi won't send follow-ups or sequence steps to, with the reason, such as a reply asking to be taken off. A reply asking to unsubscribe adds the address for you and your team, and any reply stops the follow-ups still due to that address. Outsolvi isn't a bulk sender, so keep your canonical suppression list in your main sending platform.
Put this concept into practice
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We update these pages when the underlying mechanics change. new mailbox-provider rules, new tracker behavior, new measurement gaps. The dates above are real revisions, not auto-touches.