Definition
Deliverability myths are widely held but incorrect beliefs about how mailbox providers filter and place email. These myths persist because email deliverability is complex, opaque, and constantly evolving — what was true five years ago may now be outdated. Acting on myths wastes time and can actually harm deliverability.
Common myths include focusing on individual trigger words (when modern filters use contextual analysis), obsessing over image-to-text ratios (when engagement matters far more), and believing that shorter emails always deliver better than longer ones. Understanding what actually drives deliverability — sender reputation, authentication, engagement — helps senders focus on what matters.
Common Deliverability Myths
| Myth | Reality |
|---|---|
| "Trigger words like 'free' cause spam filtering" | Modern spam filters use contextual analysis, not word blocks |
| "Images trigger spam filters" | Image blocking is different from spam filtering — properly authenticated emails with images deliver fine |
| "Short emails deliver better than long emails" | Engagement matters more than length — valuable long emails outperform short irrelevant ones |
| "You need a dedicated IP for good deliverability" | Well-managed shared IP pools perform equally well for most senders |
| "Higher volume damages your reputation" | Consistent, engaged sending at any volume is fine — sudden spikes are the issue |
| "Removing unengaged subscribers always helps" | Only if they have high complaint risk — otherwise, re-engagement may be better |
Best Practices
- Verify deliverability advice against current industry research before acting on it
- Focus on the fundamentals that mailbox providers actually measure: authentication, complaints, engagement
- Test your own emails rather than relying on general rules — every audience is different
- Stay informed about mailbox provider changes — what worked last year may not work today
- Use deliverability testing tools to measure actual inbox placement rather than guessing
- Follow authoritative sources (Gmail Postmaster, industry blogs, deliverability experts) for current best practices
Related Glossary Terms
Deliverability Audit
A deliverability audit systematically evaluates your email programme's technical setup, sending practices, and content quality to identify and fix inbox placement issues.
Deliverability Checklist
A deliverability checklist is a pre-send verification process that ensures every campaign meets the technical and content standards required for optimal inbox placement across mailbox providers.
Email Deliverability Testing
Email deliverability testing uses seed lists and inbox placement monitoring to measure what percentage of emails reach the inbox versus the spam folder across major ISPs and mailbox providers.
Delivery Rate
Email delivery rate is the percentage of sent emails that are accepted by the recipient's mail server, distinct from inbox placement rate which measures how many reach the inbox.
Gmail Promotions Tab
The Gmail Promotions Tab is a default inbox category that automatically filters marketing and promotional emails away from the Primary tab, significantly reducing visibility and open rates for commercial senders.
Primary Inbox
Primary inbox refers to the main folder where email clients deliver important messages, as opposed to promotional or social tabs in tabbed inbox systems like Gmail, where placement significantly impacts open rates.
Frequently Asked Questions
Many myths originated from early spam-filtering techniques that are now obsolete. Others come from correlation mistaken for causation — for example, shorter emails may have higher deliverability not because of length but because senders who write short emails tend to be more reputable. The email industry's complexity and lack of transparency also fuels myth persistence.
Test it yourself using inbox placement tools and controlled experiments. If a claimed "best practice" does not produce measurable results in your inbox placement, it may be a myth. Consult authoritative sources — Gmail Postmaster Tools documentation, industry studies, and deliverability specialists — rather than general marketing blogs.