What is Email Deliverability?
Email deliverability is the measure of whether your emails actually reach recipients’ primary inboxes rather than the spam folder or being blocked. It depends on authentication (SPF, DKIM, DMARC), sender reputation, list quality, content, and sending behavior like inbox warmup and volume ramp.
The main factors that control deliverability
Authentication records prove you are who you say you are. Sender reputation reflects past behavior. Engagement (opens, replies, low complaints) tells mailbox providers your mail is wanted. Warmup and gradual volume increases build that reputation safely.
How do you improve deliverability?
Set up SPF, DKIM, and DMARC correctly; warm up new inboxes; ramp volume gradually; keep lists clean; and monitor your spam score and reputation. Keres manages all of this for outbound automatically. Check your setup with the free deliverability checker and test a message with the spam score checker. For outbound, Sol, Keres AI’s AI SDR, handles this setup for you.
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SPF (Sender Policy Framework)
SPF (Sender Policy Framework) is a DNS record that specifies which mail servers are authorized to send email on behalf o…
DKIM (DomainKeys Identified Mail)
DKIM (DomainKeys Identified Mail) is an email-authentication method that adds a cryptographic signature to every message…
DMARC
DMARC (Domain-based Message Authentication, Reporting & Conformance) is a DNS policy that builds on SPF and DKIM. It tel…
Inbox Warmup
Inbox warmup is the process of gradually building a new email account’s or domain’s sending reputation before running ou…
Spam Score & Sender Reputation
A spam score estimates how likely a message or sender is to be filtered as spam, based on factors like sender reputation…
Questions
Email Deliverability — FAQ
Why are my emails going to spam?
The usual causes are missing or misconfigured SPF/DKIM/DMARC, a cold sending domain with no warmup, poor list hygiene, spammy content, or sending too much volume too fast.
What is a good deliverability rate?
For healthy outbound, you want the large majority of mail landing in the primary inbox; inbox-placement testing matters more than raw "delivered" rates, which include spam-folder delivery.
See how Sol runs outbound email
Book a free 30-minute call to go through your sending domains, your list and what Sol would send for you.
Fix your deliverabilityLast updated · Reviewed by the Keres AI team