Generic sequences are filtered by both humans and spam models. Relevant, specific openers earn replies, and reply rate is the engagement signal providers reward most.
The metrics that matter#
- Authentication pass rate: share of mail passing SPF, DKIM, and DMARC alignment. Healthy: 99% or higher.
- Spam complaint rate: Gmail enforces at 0.3%; stay under 0.1%.
- Hard bounce rate: under 2%; above 5% triggers platform reviews.
- Inbox placement: above 90% across major providers via seed tests.
- Engagement: click and reply rates by segment; opens are unreliable after Mail Privacy Protection.
Where to read them#
- Google Postmaster Tools for Gmail domain reputation, spam rate, and authentication.
- Microsoft SNDS and JMRP for Outlook.com IP reputation and complaints.
- Your ESP's delivery and bounce reports.
- DMARC aggregate reports for authentication by source.
Improving the numbers#
- Enrich contacts with 3 to 5 verifiable data points: role, company, tech stack, recent news, mutual context.
- Write a prompt template that constrains tone, length, and forbidden claims.
- Generate a first line and a value proposition per contact; keep the rest of the message stable.
- Human-review a sample of every batch before sending.
- Track reply rate per template and iterate weekly.
Frequently asked questions#
Does AI-generated email get flagged as spam?
Filters judge sender behavior and recipient reaction, not authorship. Poorly targeted AI mail gets flagged because it is poorly targeted.
How do I keep AI drafts in my voice?
Provide examples of your real sent mail and constrain style in the system prompt. MailMaid's Draft with AI learns from thread context for exactly this reason.