The Blog

Field notes on deliverability.

Hard-won lessons on email verification, inbox placement, and keeping your sender reputation spotless — from the team that's been verifying email since 2000.

Sender reputation, IP warm-up and sending infrastructure

DKIM Signing Domain vs From Domain: Which Carries Reputation?

Learn how DKIM signing domain vs From domain affects email reputation and inbox placement. Improve deliverability with precise verification and real-time.

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Email authentication: SPF, DKIM, DMARC, BIMI and MTA-STS

How to Make Salesforce Marketing Cloud Emails Pass DMARC Alignment

Ensure your Salesforce Marketing Cloud emails pass DMARC alignment. Use real-time verification and inbox placement testing to fix authentication failures.

Cold email deliverability and warm-up

Plain Text vs HTML Cold Email Reply Rate Data in 2026

Compare real plain text vs HTML cold email reply rates. Use verified data to boost response rates.

Deliverability monitoring, metrics and reporting

Why ESP Click Tracking Domains Behave Like Shorteners

Discover why ESP click tracking domains mimic shorteners and how this impacts deliverability, sender reputation, and inbox placement — with real fixes via.

Deliverability testing inside your ESP, CRM and sending platform

Amazon SES IP Option Decision Tree for Startups in 2026

Make the right Amazon SES IP choice for your startup. Use this decision tree to avoid deliverability issues and improve inbox placement.

Deliverability testing inside your ESP, CRM and sending platform

Using SendGrid, Postmark, SES Sandbox for Placement Testing

Test email inbox placement with SendGrid, Postmark, and SES sandbox. Validate deliverability before sending at scale with real-world testing.

How to test email deliverability, spam score and rendering

Testing Multipart Email Spam Score With and Without Text Part

Compare how adding a text part affects your email spam score. Use real inbox-placement testing to measure deliverability impact and avoid filtering.

How to test email deliverability, spam score and rendering

Spam Score 10 Plus: Common Causes & How to Fix Them

Discover the top reasons your emails get a spam score of 10—plus how to fix them with real verification tools and inbox placement tests.

Email authentication: SPF, DKIM, DMARC, BIMI and MTA-STS

Does BIMI or Brand Logo Affect Tab Placement?

Discover whether BIMI or a brand logo actually affects email tab placement. Learn the truths behind inbox appearance, deliverability myths, and how.

Inbox placement by mailbox provider: Gmail, Outlook, Yahoo and spam filters

Why Your Account Confirmation Email to Gmail Lands in Promotions

Stop losing users to Gmail’s Promotions tab. Learn why confirmation emails get filtered and how to verify email deliverability with accuracy.

Deliverability testing inside your ESP, CRM and sending platform

Lemlist vs Smartlead Deliverability and Sending Controls Compared

Compare Lemlist vs Smartlead's deliverability features and sending controls. See what impacts inbox placement, sender reputation, and campaign success.

Anti-spam laws and compliance: CAN-SPAM, GDPR, CASL

Unsubscribe Link and Promotions Tab Correlation in 2026

Discover how unsubscribe link placement affects promotions tab delivery. Boost inbox placement with real verification and deliverability testing using.

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Occasional, practical notes on verification and inbox placement. No spam — we'd be embarrassed.