Guides
Everything we have learned running a sending platform, written down. No gated PDFs, no signup — and no advice we would not follow ourselves.
Performance
Metrics that mean something, and how to move them.
How to improve email open rates
Open rate stopped being a reliable number in 2021. What it still tells you, what actually moves it, and how to optimise without fooling yourself.
5 min read
How to improve email click-through rate
Clicks are the first metric a human has to deliberately produce. How CTR and CTOR differ, what typical rates look like, and how to raise them.
4 min read
How to A/B test email without fooling yourself
Most email A/B tests measure noise and call it insight. Sample sizes, metric choice, and the self-deceptions that make tests worthless.
3 min read
The best time to send email — an honest answer
Every study names a different magic hour because they sample different audiences. What the data weakly supports, and what matters more than timing.
2 min read
Email segmentation that actually earns its keep
The segments that reliably pay — recency, lifecycle, behaviour — the ones that waste your time, and why two segments beat twenty.
2 min read
Re-engagement emails: winning back a quiet list
Most win-back campaigns reactivate single-digit percentages — and are worth running anyway. How to do it honestly, and when to let go.
2 min read
Email marketing metrics, defined honestly
Every email metric in one place — what it measures, what corrupts it, and which numbers deserve a place in your reporting.
2 min read
Writing
What to put in the message once it arrives.
How to write a marketing email people actually read
Structure, length, voice and formatting for email that earns a click — plus the accessibility and legal basics that stop it being deleted.
4 min read
Email subject line keywords: what works and what trips filters
There is no secret banned-word list. What actually correlates with opens, which phrases correlate with spam, and how modern filters decide.
4 min read
Preheader text: the line most senders waste
The preheader is a second subject line you get for free — and half of all senders ship “View this email in your browser” in it.
2 min read
The welcome email series: your best numbers, spent wisely
Welcome emails get several times the engagement of anything else you will ever send. What to put in that window, and how not to squander it.
3 min read
Email design: mobile, dark mode, and images that can vanish
Email renders in hostile territory — clients that block images, invert colours and cap width. Design rules that survive all of it.
3 min read
Deliverability
Getting into the inbox, and staying there.
The email deliverability checklist
Authentication, sender requirements, reputation and list hygiene — the full checklist for landing in the inbox, and what to do when you don't.
5 min read
What is a catch-all domain?
Catch-all domains accept mail for every address — which makes individual mailboxes impossible to verify. What that means for your list, and how to handle it honestly.
1 min read
How to reduce email bounce rate
Mailbox providers read your bounce rate as a measure of how much you care about your list. Practical steps to keep it under control.
1 min read
Role accounts, explained
info@, admin@, support@ — role accounts are real mailboxes with a job, not a person, behind them. Why validators flag them and how to treat them on a list.
1 min read
SPF, DKIM and DMARC, explained in plain English
The three DNS records that decide whether providers trust your mail — what each one actually does, how they fit together, and the mistakes that quietly break them.
3 min read
How to warm up an IP address (and a new domain)
Providers throttle senders with no history. A realistic warm-up schedule, the signals that say slow down, and what resets the clock.
3 min read
Email blocklists: how to check them and how to get off one
Which blocklists actually affect delivery, how to find out if you are on one, the delisting process — and why paying for removal is a scam.
2 min read
How to reduce spam complaints
The complaint rate is the one metric providers punish directly. Where complaints really come from, and how to keep the rate under 0.1%.
3 min read
Single opt-in or double opt-in?
Double opt-in costs you subscribers and protects everything else. An honest accounting of the trade, and a policy that takes both sides seriously.
3 min read
Infrastructure
How mail leaves your application.
SMTP relay or email API — which should you use?
The practical differences between sending over SMTP and sending over an HTTP API, when each one wins, and why most teams end up using both.
3 min read
Transactional vs marketing email: why they must be kept apart
Receipts and newsletters live under different laws, different expectations and different risks. Mixing them costs you both.
3 min read
Dedicated IP or shared pool? Choose by volume, not by vanity
A dedicated IP means owning your reputation alone — which is only an upgrade if you send enough to sustain one. The honest thresholds.
3 min read
Compliance
What the rules say. Not legal advice — read it as a map.
One platform behind all of it
Validation, SMTP relay, API, campaigns, automations, analytics and mailboxes — on your own domains and IPs, with a single suppression list across every path.