Blog
Deliverability and email marketing, explained properly
Field guides on sender requirements, authentication, warmup and list health — with the thresholds, tables and sources behind every claim.
Compliance · Latest
The Gmail and Yahoo bulk sender requirements: what 5,000 emails a day now costs you
Authentication, one-click unsubscribe and a spam rate under 0.10% are the price of entry for bulk senders at Gmail and Yahoo. Here is the compliance checklist, with the exact thresholds.
4 February 2026 · 9 min read
Deliverability
A 21-day domain warmup blueprint: from 50 to 50,000 emails a day
A day-by-day sending ramp for a brand-new sending domain, with the engagement gates to check before each increase and the signals that mean you should pause.
21 January 2026 · 10 min read
Technical
SPF, DKIM and DMARC alignment decoded, with the exact records to publish
Why authentication can pass and DMARC still fail, how strict and relaxed alignment differ, and the DNS records that make a sending domain trustworthy.
8 January 2026 · 11 min read
Analytics
Email benchmarks by industry: how to read open, click and unsubscribe rates in 2026
Industry benchmark ranges for open, click-through and unsubscribe rates, why Apple Mail Privacy Protection inflated every open figure since 2021, and what to measure instead.
17 December 2025 · 8 min read
Copywriting
Subject line engineering: length, structure and the six patterns worth testing
How much of a subject line a mobile inbox actually shows, what the preheader is for, and six testable subject-line structures that hold up across sectors.
3 December 2025 · 7 min read
Deliverability
List hygiene and spam traps: why removing contacts increases revenue
Pristine and recycled spam traps, the bounce and inactivity thresholds that matter, and a repeatable quarterly cleaning process.
19 November 2025 · 8 min read
Automation
Welcome sequence architecture: the first five emails, and what each one does
A five-message welcome sequence with timing, goals and exit conditions for each step — the automation that consistently outperforms the rest of the programme.
5 November 2025 · 9 min read
Infrastructure
Dedicated IP or shared pool: the volume and consistency test
A dedicated IP only helps above a volume and consistency threshold. Here is how to judge which side of it you are on, and what a dedicated IP actually changes.
22 October 2025 · 7 min read
Deliverability
Primary inbox or Promotions tab: what actually decides the placement
Gmail's categorisation is driven by engagement and content signals, not a single switch. Here is what influences it, including the HTML size ceiling that truncates messages.
8 October 2025 · 8 min read
Infrastructure
Separating marketing and transactional email streams
Why password resets and promotional campaigns should never share a sending identity, and how to split them across subdomains without losing brand recognition.
24 September 2025 · 7 min read