Deliverability

Deliverability refers to whether your messages actually reach the people you send them to. In email, this means landing in the inbox rather than the spam folder. In SMS, it means the message is delivered to the recipient’s phone rather than being blocked by the carrier. Poor deliverability means your campaigns reach fewer people than you think — even if your platform reports high “sent” numbers.

What Determines Email Deliverability

Email deliverability is primarily a function of your sender reputation — how mailbox providers (Gmail, Outlook, Yahoo) perceive your sending behavior. Key factors include: your sender score and IP reputation, whether you have SPF, DKIM, and DMARC authentication set up, the engagement rate of your previous sends (mailboxes that never open your emails signal spam), and the quality of your list (invalid or inactive addresses hurt your reputation).

SMS Deliverability

SMS deliverability is affected by different factors: carrier filtering (carriers block messages that look like spam), regulatory compliance (non-opt-in sends are blocked), and the quality of your message content. Certain words and phrases that appear in known spam campaigns trigger carrier filters. Using a reputable SMS platform with proper 10DLC registration (in the US) significantly improves delivery rates.

How to Maintain Strong Deliverability

The most reliable deliverability practices are: send only to people who have opted in, maintain list hygiene by removing inactive addresses regularly, authenticate your sending domain, monitor your bounce and spam complaint rates, and gradually warm up new sending IPs rather than sending high volumes immediately. Deliverability is not a one-time setup — it requires ongoing maintenance.