Email deliverability questions, answered
One page per question. Each answer leads with the verdict, cites the vendor documentation behind every number, and ends with the fix.
What is a good email bounce rate?
Under 1% is healthy, 2% needs investigating, 5%+ is an emergency. The bounce-rate benchmarks ESPs actually publish, plus the triage table to fix yours.
Read the answer →Why are my Mailchimp emails going to spam?
Mailchimp campaigns landing in spam? The four real causes: unauthenticated sending domain, shared IP reputation, list decay, engagement. And the DNS fix.
Read the answer →How to authenticate email for marketing
The platform-agnostic setup order: sending subdomain, SPF include, custom DKIM, DMARC with rua, alignment check, policy ramp. With live ESP doc links.
Read the answer →What is SPF flattening?
SPF flattening swaps include: mechanisms for raw IPs to beat the 10-lookup limit. When it helps, when it silently breaks, and the alternatives that age better.
Read the answer →Why are my newsletters going to spam?
Four causes: failed SPF/DKIM/DMARC, no one-click unsubscribe, complaints over 0.3%, dead engagement. What Gmail and Yahoo actually require, plus the fix.
Read the answer →What is Google Postmaster Tools?
Google Postmaster Tools explained: the v2 dashboards, DNS TXT setup, the 0.3% spam-rate line, and how to read it before moving DMARC to p=reject.
Read the answer →What is Microsoft SNDS?
SNDS is Microsoft's free per-IP reputation portal for Outlook.com senders. What it shows, how to sign up, its limits, and how it pairs with DMARC reports.
Read the answer →What are DMARC aggregate reports?
Daily XML files sent to your rua address: every source IP, message counts, disposition, SPF/DKIM results. What's inside one and how to read it.
Read the answer →Why is DMARC failing but SPF passes?
SPF checks the Return-Path domain; DMARC needs it to match your From domain. Why ESP bounce domains, forwarding, and strict aspf break alignment.
Read the answer →How do I move from DMARC p=none to p=reject?
The staged playbook from p=none to p=reject: monitor with rua, fix alignment per sender, ramp pct through quarantine, then enforce. Timelines and rollback.
Read the answer →Does DMARC affect email marketing?
Yes. Google and Microsoft require DMARC for bulk senders, misalignment sends campaigns to spam, and enforcement unlocks your BIMI logo in the inbox.
Read the answer →Why did my email get clipped in Gmail?
Gmail clips HTML over ~102KB behind a View entire message link. What counts toward the limit, why it hurts opens and unsubscribes, and how to slim the template.
Read the answer →Decoding a specific bounce code instead? Look it up in the SMTP error-code reference →