Checklist
14 steps to make your email campaigns actually reach the inbox
A weak subject line shows up as a low open rate. A bad CTA shows up as a low click-through rate. Deliverability problems don't surface anywhere obvious – they show up as absence. Fewer replies, lower engagement, pipeline that never materialises. By the time you investigate, the sends are paid for and the leads are gone.
1 in 5
legitimate marketing emails fails to reach the inbox globally.
For senders without proper authentication and hygiene, this number is significantly worse.
Why email deliverability is a marketing problem, not just an IT problem
Inside this guide, you will discover:
- Why deliverability fails silently – and how that absence translates into lost pipeline long before anyone in the team notices.
- The five DNS protocols (SPF, DKIM, DMARC, MX, BIMI) that prove your emails are legitimate – what each one does, how to confirm it's working, and exactly what to ask your IT team for.
- The six compliance standards that keep you filter-friendly – consent management, double opt-in, transparent headers, one-click unsubscribe, full sender identification, and TLS-secured delivery — all aligned with CSA criteria and the GDPR.
- The three reputation practices that determine inbox placement over time, including the 0.3% complaint rate and 1.0% hard bounce ceilings that trigger ISP throttling.
- A printable 14-item scorecard mapping every check to its owner (marketing, IT/DevOps, or joint) so you know exactly what to fix first.
Authentication is the cost of entry. Reputation is the compounding return.
DNS records get configured once. Reputation is built every send. Most programs that fail deliverability don't fail at setup — they fail in the gap between "we authenticated the domain" and "it still works six months later, after three new vendors started sending on it." The checklist closes that gap by giving you the thresholds, the ownership map, and the exact questions to put in front of your IT team.
If you own the email program but not the DNS zone file, if you've been told deliverability is an IT issue, or if you can't explain why a campaign's open rate quietly dropped, this whitepaper gives you the vocabulary and the framework to take the conversation back.
Get a 14-step checklist built on the Certified Senders Alliance standards — the quality benchmark used by major European mailbox providers — distilled into a reference you can share with IT, print, and pin next to your campaign planning board.
Deliverability is the share of your legitimate emails that actually reach the inbox, rather than landing in spam or being silently rejected. Sending is a technical action — the email leaves your server. Deliverability is what happens next: whether mailbox providers like Google or Microsoft decide the message deserves trust. It's controlled by three factors — legal consent, technical authentication, and the sender reputation you build over time — and it fails silently, showing up as fewer replies and lower engagement rather than a visible error.
Deliverability is the share of your legitimate emails that actually reach the inbox, rather than landing in spam or being silently rejected. Sending is a technical action — the email leaves your server. Deliverability is what happens next: whether mailbox providers like Google or Microsoft decide the message deserves trust. It's controlled by three factors — legal consent, technical authentication, and the sender reputation you build over time — and it fails silently, showing up as fewer replies and lower engagement rather than a visible error.
The CSA is a joint initiative by eco (Association of the Internet Industry) and the German Dialogue Marketing Association. It's the most widely recognised quality benchmark for commercial email senders in Europe. Meeting CSA criteria means your email program aligns with what major mailbox providers actually evaluate when deciding whether to deliver, throttle, or block your messages. The 14 checks in this whitepaper are built directly on CSA standards.
The CSA is a joint initiative by eco (Association of the Internet Industry) and the German Dialogue Marketing Association. It's the most widely recognised quality benchmark for commercial email senders in Europe. Meeting CSA criteria means your email program aligns with what major mailbox providers actually evaluate when deciding whether to deliver, throttle, or block your messages. The 14 checks in this whitepaper are built directly on CSA standards.
The three protocols work as layers. SPF (Sender Policy Framework) is a DNS record listing every server authorised to send email on behalf of your domain. DKIM (DomainKeys Identified Mail) adds a cryptographic signature to each message, proving it came from an authorised source and wasn't altered in transit. DMARC ties the two together: it tells receiving mail servers what to do when an email fails SPF or DKIM, and sends you reports on the failures. You need all three. SPF and DKIM are the credentials; DMARC is the policy that enforces them.
The three protocols work as layers. SPF (Sender Policy Framework) is a DNS record listing every server authorised to send email on behalf of your domain. DKIM (DomainKeys Identified Mail) adds a cryptographic signature to each message, proving it came from an authorised source and wasn't altered in transit. DMARC ties the two together: it tells receiving mail servers what to do when an email fails SPF or DKIM, and sends you reports on the failures. You need all three. SPF and DKIM are the credentials; DMARC is the policy that enforces them.
The CSA threshold is 0.3% per seven-day period at any given mailbox provider, measured per IP address, per DKIM domain, or per sender. At 0.3%, the CSA and most major mailbox providers start taking action — throttling, filtering to spam, or outright blocking. Even below that ceiling, a rising trend is a warning sign. The complaint rate is the single most important reputation metric to monitor weekly.
The CSA threshold is 0.3% per seven-day period at any given mailbox provider, measured per IP address, per DKIM domain, or per sender. At 0.3%, the CSA and most major mailbox providers start taking action — throttling, filtering to spam, or outright blocking. Even below that ceiling, a rising trend is a warning sign. The complaint rate is the single most important reputation metric to monitor weekly.
Both — but the consequences land on marketing's desk. DNS records, authentication protocols, and TLS encryption are configured by IT or DevOps. Consent flows, unsubscribe experience, sender naming, and list hygiene are owned by marketing. When deliverability fails, the cost shows up as wasted budget, missed leads, and brand credibility eroded quietly in the background. The 14-item checklist in this whitepaper maps every check to its owner (marketing, IT/DevOps, or joint), so the right person fixes the right thing.
Both — but the consequences land on marketing's desk. DNS records, authentication protocols, and TLS encryption are configured by IT or DevOps. Consent flows, unsubscribe experience, sender naming, and list hygiene are owned by marketing. When deliverability fails, the cost shows up as wasted budget, missed leads, and brand credibility eroded quietly in the background. The 14-item checklist in this whitepaper maps every check to its owner (marketing, IT/DevOps, or joint), so the right person fixes the right thing.
Which problem can we solve for you?
JustRelate's Automations engine is CSA-certified by design, with the authentication, compliance, and reputation standards in this checklist built into the platform. If you'd like to see what that looks like applied to your own sending infrastructure, let's talk.