Latest Articles
Practitioner notes on outbound email infrastructure, deliverability engineering, and what the AI era is doing to both.
2026-06-10AI Email & Deliverability
AI Personalization in Email: What Actually Improves Deliverability
Which AI personalization techniques improve email deliverability and engagement, and which are hype. Data-backed analysis of subject lines, content, send time, and segmentation.
2026-06-10AI Email & Deliverability
Email Deliverability for AI SDR Agents: The 2026 Engineering Guide
AI SDR agents change the deliverability math: machine volume and clustered content. An engineering guide to mailbox math, content variation, and monitoring.
2026-06-10Cold Email Infrastructure
Cold Email Infrastructure: The Complete Setup Guide for Serious Outreach
How to build cold email infrastructure that lands in the inbox: secondary domains, mailbox math, SPF/DKIM/DMARC, 14-30 day warmup, sequencer config, and monitoring.
2026-06-10Cold Email Infrastructure
Cold Email Templates for Government Contractors and Consultancies
Cold email templates for government contractors, consultancies, and professional services — what works in formal industries, with sender deliverability guidance.
2026-06-10Cold Email Infrastructure
The GTM Email Infrastructure Stack (2026): Every Layer, Explained
Every layer of the 2026 GTM outbound email stack — data, verification, sending domains, sequencers, AI SDRs, monitoring — with real costs and failure modes.
2026-06-10Cold Email Infrastructure
What Outbound Email Infrastructure Costs in 2026 (Real Numbers)
Real 2026 numbers for cold email infrastructure: domains, mailboxes, sequencers, verification, and worked cost tables for 1 SDR, 5 SDRs, and AI agent fleets.
2026-06-10definitions
What Is Cold Emailing? Definition and How It Works
Cold email is unsolicited outreach to a recipient with whom you have no prior relationship. Here's the definition, how it differs from spam, and the sender mechanics.
2026-06-10definitions
What Is MTA-STS? (Mail Transfer Agent Strict Transport Security)
MTA-STS forces encrypted TLS connections for email delivery to your domain, preventing downgrade attacks and man-in-the-middle interception of email in transit.
2026-06-10Email Authentication
Office 365 DKIM Setup: The Complete Guide
Set up DKIM in Office 365 (Microsoft 365 / M365 / Exchange Online) the right way. Generate keys, publish DNS records, enable signing — with screenshots and verification steps.
2026-06-10Email Authentication
ARC: Solving the DMARC Problem with Email Forwarding
What ARC (Authenticated Received Chain) is, why it matters for forwarded email, and how it preserves authentication through mailing lists and forwarding services.
2026-06-10Email Authentication
What is BIMI? Complete Guide to Brand Indicators for Message Identification
BIMI displays your brand logo next to emails in supported inboxes. Learn how BIMI works, the requirements, and whether it's worth the investment.
2026-06-10Email Authentication
BIMI VMC: DigiCert vs Entrust — Which Certificate Authority to Choose
Compare DigiCert and Entrust for BIMI Verified Mark Certificates. Pricing, process, timeline, and which is right for your organization.
2026-06-10Email Authentication
DKIM Alignment Explained: How DMARC Uses It
DKIM alignment is the rule that DKIM's signing domain must match the From: header for DMARC to pass. Here's how relaxed vs strict alignment actually works.
2026-06-10Email Authentication
DKIM CNAME vs TXT Records: Which Should You Use?
DKIM CNAME vs TXT records compared: when each is used, ESP behavior, key rotation implications, and how to debug DKIM lookups when records don't resolve.
2026-06-10Email Authentication
DKIM 1024-bit vs 2048-bit: Which Key Length to Use
Choose the right DKIM key length. Understand why 2048-bit is now standard, when 1024-bit is acceptable, and how to upgrade your DKIM keys.
2026-06-10Email Authentication
DKIM Selector Examples: Naming, Rotation, and Multi-Selector Setup
DKIM selector examples from real ESP configurations — naming conventions, rotation patterns, and how to run multiple selectors safely for the same domain.
2026-06-10Email Authentication
Reading DMARC Aggregate Reports Like a Pro
DMARC aggregate report reading: how to parse the XML, interpret DMARC tags (adkim, aspf, p, sp, fo), and use reports to move from p=none to p=reject safely.
2026-06-10Email Authentication
DMARC Alignment: SPF Alignment vs DKIM Alignment
Understand DMARC alignment — how SPF and DKIM results must align with the From domain. Learn relaxed vs strict alignment and how to fix alignment failures.
2026-06-10Email Authentication
DMARC for Parked Domains (You Still Need It)
Do you need DMARC on parked or no-mail domains? Yes. Here's how to publish a defensive DMARC record on domains that never send mail to block spoofing.
2026-06-10Email Authentication
Advancing from p=none to p=reject: The Safe Timeline
Move your DMARC policy from p=none to p=reject safely. A week-by-week timeline with checkpoints to prevent breaking legitimate email.
2026-06-10Email Authentication
DMARC Setup for Office 365: Step-by-Step
Configure DMARC for Office 365 / Microsoft 365 (M365) the right way. Add the TXT record, advance from p=none to p=reject, and monitor reports. Full walkthrough.
2026-06-10Email Authentication
DMARC Report Parsers Compared: Free and Paid
DMARC report parser comparison: dmarcian, Postmark DMARC, EasyDMARC, Valimail, and open-source options. Pick the right parser for your scale and budget.
2026-06-10Email Authentication
DNS Records for Email: The Complete Guide
Every DNS record needed for sending and receiving email — MX, SPF, DKIM, DMARC, BIMI, MTA-STS, TLS-RPT — with examples and ordering.
2026-06-10Email Authentication
Email Authentication Audit Checklist: Verify Everything Is Correct
A complete checklist for auditing your domain's email authentication. SPF, DKIM, DMARC, MTA-STS, BIMI — verify every record, every setting, every alignment.
2026-06-10Email Authentication
SPF, DKIM, DMARC: The Complete Email Authentication Guide
Set up SPF, DKIM, and DMARC correctly the first time. This guide covers every protocol, every configuration option, and every mistake that breaks authentication.
2026-06-10Email Authentication
SPF With Multiple Email Providers: Combining Records Safely
How to combine SPF records when using multiple email providers (Google Workspace, SendGrid, Mailchimp) without exceeding the 10-lookup limit or breaking authentication.
2026-06-10Email Authentication
What Is DKIM? Complete Guide to DomainKeys Identified Mail
DKIM adds a cryptographic signature to your email proving it wasn't altered in transit. How it works, why it matters for DMARC, setup process, and common failures.
2026-06-10Email Authentication
What Is DMARC? Complete Guide for 2026
DMARC ties SPF and DKIM together and tells receiving servers what to do when authentication fails. How it works, why it's mandatory, policy levels, and reporting.
2026-06-10Email Authentication
What Is SPF? Complete Guide to Sender Policy Framework
SPF (Sender Policy Framework) tells receiving servers which IPs can send email for your domain. How it works, why it matters, record syntax, common mistakes, and how to set it up.
2026-06-10Email Automation
Re-Engagement Email Campaign: Timing, Strategy, and List Hygiene
Build a re-engagement campaign that recovers inactive subscribers and cleans your list. Includes timing, email templates, and when to remove contacts for good.