Email Best Practices
for Klaviyo Senders
Klaviyo handles campaign sending, flows, and SMS — but inbox placement depends on decisions that live outside the platform. This six-part series covers the ones that matter most: compliance, list quality, capture strategy, message types, domain warming, and spam trap prevention. With Gmail, Yahoo, Microsoft, and Apple all enforcing authentication, one-click unsubscribe, and spam-rate thresholds, these practices are now the price of entry.
Email Compliance
CAN-SPAM, GDPR & CASL
Legal requirements for your email campaigns — unsubscribe setup, consent documentation, and a per-campaign compliance checklist.
List Management
Hygiene, Suppression & Re-engagement
How to keep your email list clean — bounce handling, suppression lists, engagement segments, and win-back campaigns.
Email Capture
Opt-In, Forms & Validation
Build a high-quality list from day one — double opt-in setup with your platform, form design, email validation, and abuse prevention.
Transactional vs Marketing
Two Streams, Two Reputations
How Klaviyo handles each message type, when to add a dedicated transactional ESP, and why one shared reputation damages both streams.
IP & Domain Warming
8-Week Ramp Schedule
How to warm up your sending domain correctly — week-by-week volume targets, metrics to watch, and what to do if inbox placement drops.
Spam Traps
Types, Prevention & Recovery
What email spam traps are, the 5 types including role-based addresses, how they end up on your list, and a step-by-step recovery plan if you've been blacklisted.
Mailbox Provider Rules Now in Effect
One-Click Unsubscribe Required
Google, Yahoo, and Apple require List-Unsubscribe with one-click (RFC 8058) on bulk marketing email; Microsoft recommends it. Microsoft has rejected non-compliant mail at the SMTP level since May 2025 — bounced outright, not filtered.
Authentication & Alignment
Send 5,000+/day to Gmail, Yahoo, or Outlook and all three require SPF, DKIM, and DMARC, with your From: domain aligned to the SPF or DKIM domain. p=none is a starting point, not a destination — providers expect progression toward quarantine or reject.
BIMI Boosts Brand Trust
Once DMARC is enforced, a BIMI record with a VMC or Common Mark Certificate (CMC) displays your logo in Gmail and Yahoo inboxes — increasing brand recognition and inbox trust.
Spam Rate Below 0.30%
Bulk senders must keep complaint rates under 0.30%; treat 0.10% as your working ceiling. Gmail and Yahoo score reputation in real time from opens, clicks, and immediate deletes — engagement quality now outweighs volume.
Why Klaviyo Senders Need a Deliverability Strategy
Klaviyo handles campaign sending, flows, and SMS — but inbox placement depends on factors that live outside it: your DNS authentication records, your list quality, how you capture subscribers, and your sending domain's reputation history.
Mailbox providers like Gmail and Outlook evaluate every sender independently. Even on shared sending infrastructure, your domain builds its own reputation from how your subscribers respond. Complaints, bounces, and low engagement hurt your reputation — not your ESP's. The six guides below give you a complete framework for protecting that reputation, from the moment subscribers sign up through every campaign send.
Related Resources
Monitor Your Email Deliverability
InboxEagle monitors inbox placement, domain reputation, DMARC compliance, bot detection, and blacklist status for your sending domain — with real-time alerts when anything changes.