Koltrix
Guides
Moving Your Company Email to a New Domain After a Rebrand
A rebrand means new email addresses, but the old domain keeps receiving mail for years. How to switch addresses, authenticate both domains and avoid lost mail.
5 min read
DeliverabilityLookalike domains: detecting cousin-domain phishing
Typo and homoglyph domains pass authentication for themselves. Monitor new registrations, register obvious variants and train people to check senders.
4 min read
Email APISending email on behalf of your customers' domains
SaaS platforms that send as their customers need domain verification, per-tenant DKIM and isolated reputation. The architecture and the onboarding flow.
5 min read
DeliverabilitySeparate subdomains for transactional and marketing mail
Splitting streams across subdomains contains reputation damage. How to structure them, align SPF and DKIM per subdomain, and what it cannot protect.
4 min read
GuidesPicking a Domain With Email in Mind
Your domain ends up in every address you hand out. How to pick one that is easy to say, hard to spoof, and safe from the registrar mistakes that lose email.
4 min read
DeliverabilityWarming up a brand-new sending domain
A new domain has no reputation, which filters treat with suspicion. Authenticate first, start with your most engaged recipients and grow steadily.
5 min read