Deliverability is not about avoiding spam words in your subject line. That is a myth from 2010. Modern email filtering is based on sender reputation, authentication, and engagement signals. Here is what actually moves the needle.
DNS Authentication: The Foundation
If you do nothing else, set up these three DNS records. Without them, Gmail and Outlook will treat your emails as suspicious.
HIGH
SPF (Sender Policy Framework)
Tells receiving servers which IP addresses are authorized to send email from your domain. Without SPF, anyone can spoof your domain.
How: Add a TXT record to your domain DNS. Your email platform provides the exact value copy it from their authentication settings.
HIGH
DKIM (DomainKeys Identified Mail)
Adds a cryptographic signature to every email proving it was not tampered with in transit. Gmail weighs DKIM heavily in spam filtering.
How: Add a CNAME record to your DNS. Your platform generates the key pair you just add the public key as a DNS record.
HIGH
DMARC (Domain-based Message Authentication)
Tells receiving servers what to do with emails that fail SPF/DKIM checks. Also gives you reports on who is sending email from your domain.
How: Add a TXT record at _dmarc.yourdomain.com. Start with p=none (monitor only), then move to p=quarantine after reviewing reports.
Google & Yahoo 2024 Requirements
Since February 2024, Gmail and Yahoo require SPF or DKIM authentication for all bulk senders (5,000+ emails/day). DMARC is required for bulk senders. If you send marketing emails without these records, your emails will be rejected not just filtered to spam, but bounced entirely.
List Hygiene
HIGH
Remove hard bounces immediately
Hard bounces (invalid addresses) damage your sender reputation fast. Most platforms auto-remove them, but verify this is enabled. Target: 0% hard bounce rate.
HIGH
Clean inactive subscribers every 90 days
Subscribers who have not opened in 90 days drag down your engagement metrics. Run a re-engagement campaign first, then remove non-responders. A smaller, engaged list outperforms a large, dead one.
MEDIUM
Use double opt-in
Require new subscribers to confirm their email address. This eliminates typos, bots, and fake signups. Your list grows slower but every contact is verified and engaged.
CRITICAL
Never buy or rent email lists
Purchased lists contain spam traps addresses specifically designed to catch spammers. One spam trap hit can blacklist your entire domain. There is no shortcut here.
HIGH
Monitor spam complaint rate
Keep spam complaints below 0.1% (1 per 1,000 emails). Gmail Postmaster Tools shows your complaint rate. If it exceeds 0.3%, you will see immediate deliverability drops.
Content Best Practices
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Use a recognizable sender name
People open emails from names they recognize. Use "John at CompanyName" or just "CompanyName" not "noreply@" or random addresses.
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Keep text-to-image ratio balanced
Emails that are 100% images get flagged. Aim for 60% text, 40% images. Always include alt text on images.
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Include a plain text version
Most platforms generate this automatically. Plain text versions improve deliverability and accessibility.
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One clear unsubscribe link
Make it easy to unsubscribe. Hidden or broken unsubscribe links lead to spam complaints, which are far worse for your reputation.
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Do not use URL shorteners
Bit.ly and similar shorteners are heavily used by spammers. Use full URLs or your platform built-in link tracking.
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Do not use all caps or excessive punctuation
"FREE!!! CLICK NOW!!!" triggers spam filters and annoys readers. Write like a human, not a late-night infomercial.
Technical Checklist
Run through this before every campaign:
Platform Deliverability Scores
From our 6-month testing across all platforms we review:
Platform Matters Less Than You Think
The difference between the best and worst platform is only 6%. Your own practices authentication, list hygiene, content quality, sending consistency account for 80%+ of your deliverability. A bad sender on GetResponse will have worse deliverability than a good sender on Constant Contact.
FAQ
How do I check if my emails are going to spam??
Does using a free email plan hurt deliverability??
How long does it take to fix bad deliverability??
Should I use a dedicated IP??
Do spam trigger words still matter??
What is a good inbox placement rate??
What Actually Matters
Deliverability is 80% your practices, 20% your platform. Set up SPF, DKIM, and DMARC today takes 30 minutes and has the biggest single impact. Clean your list every 90 days. Watch your spam complaint rate. Do those three things and you'll outperform most email senders.
Platforms With Best Deliverability
| GetResponse | 94.2% inbox rate Best automation | Try Free ? |
| Brevo | 93% inbox rate Best free plan | Try Free ? |
| MailerLite | 90% inbox rate Easiest setup | Try Free ? |