Koltrix
Guides
Leaving Web-Host Email (cPanel) for a Real Business Inbox
The email bundled with your web hosting was fine to start with. Why it causes trouble as you grow, and how to move mail off cPanel without breaking your site.
5 min read
Team inboxWhy two people answer the same email, and five fixes
A teardown of a duplicate-reply incident in a shared inbox: the five root causes behind it, fixes ranked by effort, and how to apologize when it still happens.
5 min read
DeliverabilitySpamhaus listings explained: SBL, XBL, PBL, CSS, DBL
Spamhaus runs several blocklists with different causes and fixes. What each one means for a sender, how to check a listing and where to start.
5 min read
StartupsConverting No-Card Trials: What to Email and When
No-card trials bring more signups and more tire-kickers. How to email them: qualify early, ask for payment at the right moment, and handle the lapse with care.
4 min read
AI & emailReviewing AI-drafted replies: a 60-second checklist
A quick checklist for reviewing AI-drafted email replies before you send: recipients, facts, promises, tone, links and the things a model simply can't know.
4 min read
Email APIUnicode in email: SMTPUTF8, encoded headers and IDNs
Non-ASCII names, subjects and addresses need different mechanisms. How RFC 2047 encoded words, SMTPUTF8 and IDN domains fit together in practice.
4 min read
GuidesMigrating Email Away From Zoho Mail, Step by Step
How to move a domain's mail off Zoho Mail without losing messages: export options, recreating aliases and groups, DNS changes, and checking every integration.
5 min read
Customer supportA triage matrix for support email: urgency vs impact
Sort support email by urgency and impact with a simple 3x3 matrix, see real examples placed in each cell, and get the right response for every combination.
4 min read
DeliverabilityDKIM replay attacks: how signed mail gets abused
A single legitimately signed message can be resent to millions. How DKIM replay works, why it hurts your domain, and the mitigations available today.
4 min read
StartupsEmail Cadence for a 7-Day Trial vs a 30-Day Trial
Trial length changes how many emails you send, when, and what each one does. Side-by-side schedules for 7-day and 30-day trials, and how to choose a length.
4 min read
GuidesAn AI email policy template for small teams
A copyable AI email policy for small teams: approved tools, data limits, human review before send, sensitive mailboxes, disclosure and incident reporting.
5 min read
Email APIPassword reset emails: token design and delivery checklist
Reset emails are a top account takeover vector. Design single-use, short-lived tokens, avoid account enumeration and make the email arrive fast.
4 min read