Email Deliverability Guide
MZ Messenger
The Invisible Problem Killing Your Campaigns
Your email campaign looks perfect. Great subject line. Compelling copy. Strong call-to-action. You hit send to 10,000 subscribers and wait for the results. But here's what you don't see: 30% of your emails never reach the inbox. They're not bouncing. They're not marked as spam. They're just... gone. Filtered into spam folders, blocked by ISPs, or disappeared into the void. That's the deliverability problem. And it's costing you more than you think.
Why Good Emails Go to Spam
What Email Deliverability Actually Means
Deliverability isn't about whether your email gets delivered. That's a different metric (delivery rate).Deliverability is about where your email lands:
The inbox? Great—your subscriber will probably see it
The spam folder? Not great—99% chance they'll never see it
The promotions tab? Depends—some people check it, most don't
Completely blocked? You won't even know it happened
Most email platforms will tell you "98% delivered!" But they're not telling you that half of those went to spam.
MZ Messenger
The Technical Stuff That Actually Matters
SPF (Sender Policy Framework)
What it is: A list of servers allowed to send email on behalf of your domain
Why it matters: Without SPF, anyone can pretend to be you. ISPs don’t trust emails that can’t prove their origin.
How to fix it: Add an SPF record to your DNS settings. It looks like this: v=spf1 include:alertmessenger.com ~all
Your email platform should provide exact instructions. This takes 10 minutes and solves a massive problem.
DKIM (DomainKeys Identified Mail)
What it is: A digital signature that proves your email wasn’t modified in transit
Why it matters: Email can be intercepted and changed. DKIM proves what you sent is what they received.
How to fix it: Your email platform generates a DKIM key. You add it to your DNS. Again, follow your platform’s instructions—it’s easier than it
sounds.
DMARC (Domain-based Message Authentication, Reporting, and Conformance)
What it is: Instructions for what ISPs should do if SPF or DKIM fails
Why it matters: Without DMARC, ISPs guess what to do with suspicious emails. With DMARC, you tell them.
How to fix it: Add a DMARC record to DNS that tells ISPs to reject emails that fail authentication: dmarc@yourdomain.com
Important: Set up SPF and DKIM first. DMARC builds on those.
List Hygiene: The Foundation of Deliverability
Here’s something most marketers don’t want to hear: a smaller, engaged list outperforms a large, inactive one every single time.
Remove these people from your list:
Here’s something most marketers don’t want to hear: a smaller, engaged list outperforms a large, inactive one every single time.
Remove these people from your list:
Hard bounces – Email addresses that don’t exist. Remove them immediately.
Repeated soft bounces – Full inboxes or temporary issues. If it happens 3+ times, they’re gone.
Never-openers – Haven’t opened an email in 6+ months? They’re hurting your reputation.
Spam complainers – Someone marks you as spam? Remove them fast. ISPs track this closely.
Role addresses – admin@, info@, sales@ rarely get monitored and often cause problems.
One of our customers removed 40% of their list — Yes, 40%—after realizing they were paying to email people who never engaged. Their open rates jumped from 15% to 34%, and their revenue per campaign doubled. Same emails. Better audience.
The Warm-Up Process (For New Senders)
Starting with a new domain or IP address? You can’t just blast 50,000 emails on day one.ISPs treat new senders like strangers. You need to build trust gradually:
Week 1: Send to your 50-100 most engaged subscribers
Week 2: Increase to 200-500 Week
Week3: Double again to 500-1,000
Week 4: Keep doubling until you reach full volume
This process takes 4-6 weeks, but it’s the difference between landing in inboxes and getting blocked entirely.
DKIM (DomainKeys Identified Mail)
Shared IP vs. Dedicated IP
Shared IP – You share an IP address with other senders. Good: lower cost, established reputation. Bad: someone else's bad behavior can hurt you.
Dedicated IP – You get your own IP address. Good: complete control. Bad: you're starting from zero reputation and need to warm it up.
For most businesses sending under 100,000 emails per month, shared IPs work great—if you're with a good provider who maintains clean infrastructure.
Custom domain for sending:
Don't send from your main company domain (company.com). Use a subdomain (mail.company.com or emails.company.com).
Why? If something goes wrong with your email sending, it won't hurt your main domain's reputation.
Monitoring Your Deliverability
The Deliverability Checklist
SPF, DKIM, and DMARC are set up correctly
List has been validated recently
Hard bounces and complainers removed
Sending from a warmed-up domain/IP
Subject line and content avoid spam triggers
Clear from name and working reply-to address
Prominent, easy-to-find unsubscribe link
Mobile-friendly design
Sending to engaged subscribers who opted in[ ] Content provides genuine value