Koltrix
Guides
What to Do With the Old Mailbox After You Migrate
The MX records have moved and new mail is flowing. Now decide what happens to years of old email: keep it, export it, archive it, or let it go, and when.
5 min read
AI & emailCorrecting misclassified email: building a feedback loop
A playbook for fixing AI email sorting mistakes: move the message, spot the pattern, add rules only when they are exact, and keep a weekly misfile log.
4 min read
DeliverabilityDetecting a compromised account sending spam as you
A hijacked mailbox or leaked SMTP credential can burn your domain reputation in hours. The signals to watch and the containment steps to rehearse.
4 min read
StartupsExit Survey Emails: Questions That Get Honest Answers
A short exit survey by email can tell you more about churn than any dashboard. Which questions to ask, how to format them, and what to do with the answers.
5 min read
GuidesConverting your logo to SVG Tiny PS for BIMI
BIMI requires the SVG Tiny Portable/Secure profile. What that profile forbids, how to convert a normal SVG, and the validation errors you will likely hit.
5 min read
Team inboxInbox zero for teams: a workable definition and daily routine
Team inbox zero means every thread has a clear state, not an empty screen. Here is a definition that holds up and a time-boxed daily routine to reach it.
4 min read
GuidesEmail Migration Rollback Plan: When the Cut-Over Goes Wrong
Most email migrations go fine, but the bad ones go badly fast. A rollback plan: triggers, the DNS values to save, and how to reconcile mail after reverting.
5 min read
Customer supportHandling angry customer emails: a calm, repeatable approach
A playbook for replying to angry customer emails: find the real problem, answer without defensiveness, offer a next step, and know when to set boundaries.
4 min read
Email APIImplementing one-click unsubscribe (RFC 8058) correctly
One-click unsubscribe needs two headers, a DKIM signature that covers them, and an endpoint that accepts a POST without a login. Build it step by step.
5 min read
StartupsWin-Back Emails for Churned SaaS Customers: Timing and Tone
Not every churned customer should get a win-back email. How to choose who to contact, when to write, what to say, and when to stop emailing for good.
5 min read
GuidesHow to build an email triage rota for a team of three to ten
A runbook for a shared-inbox triage rota: shift length, triager duties, handoffs, fairness, holidays, and a sample two-week schedule for small teams.
4 min read
DeliverabilityShared vs dedicated sending IPs: a decision guide
Dedicated IPs give you control and responsibility; shared pools give you a neighbor's reputation. Volume thresholds and questions to decide well.
4 min read