The Email Deliverability Checklist I Run for Every Newsletter

Sending a newsletter is easy. Getting it into inboxes is the real work. I run the same deliverability checklist before every major send and it consistently keeps me out of spam folders. Here is the full list and the handful of tools I use to check each item before I hit send.

The Pre-Send Checks

1. SPF record published on the sending domain
2. DKIM signing verified by the provider
3. DMARC policy at least quarantine
4. Unsubscribe header present and functional
5. List cleaned of hard bounces in the last 30 days
6. Preview text under 100 characters
7. Image-to-text ratio below 60 percent images
8. Subject line under 50 characters, no all-caps
9. At least one plain-text alternative body

The Tools I Use

• mail-tester.com for a single pre-flight score
• mxtoolbox.com for DNS record verification
• Gmail Postmaster Tools for reputation history
• dmarcian.com for DMARC policy review

The Reputation Rule

Deliverability is a reputation game. One bad send with a dirty list drops your deliverability for weeks. I would rather send to a smaller clean list than a larger stale one. Reputation is slow to build and fast to lose. Treat it like a credit score.

Before every send:
- Remove any address that bounced in last 30 days
- Remove any address that has not opened in 180 days
- Verify the list size matches the ESP's free/paid tier
- Check the sending IP warmup schedule if it is a new IP

What I Learned the Hard Way

Sending to a stale 5000-address list tanked my reputation for a month. Cleaning it to 2000 active addresses doubled my open rate and restored deliverability. Size is vanity, engagement is revenue. That was the most expensive lesson I have learned about email, and I learned it by ignoring the rule I just told you.

The Send Cadence Part

Consistent cadence matters as much as clean lists. Sending once a week for six months trains inbox providers to expect your mail. A gap of three months and then a sudden send looks like spam to every major provider.

The Warmup Strategy

Any new domain or IP needs two to four weeks of gradual ramp-up before you send at full volume. Skipping warmup is the most common deliverability mistake I see new senders make.