Koltrix
Deliverability
DMARC for subdomains: sp=, np= and domains you forgot
Attackers love subdomains you never configured. How sp= and the new np= tag cover them, how policy discovery works, and when to publish per-subdomain records.
4 min read
Blog · Deliverability · page 5 of 5
Deliverability
SPF, DKIM, DMARC, BIMI, sender reputation and the inbox rules of Gmail, Yahoo and Microsoft: what decides whether your email arrives.
DeliverabilityBusiness email compromise: invoice fraud red flags
BEC scams change bank details or rush payments through email. Spot the red flags, add out-of-band verification and harden accounts against takeover.
4 min read
DeliverabilitySpam traps: pristine, recycled and typo traps explained
Spam traps are addresses that should never receive your mail. How each type ends up on lists, what hitting them signals and how to stop it happening.
5 min read
DeliverabilitySpam filter myths: trigger words, images and link counts
Modern filters care far more about reputation and engagement than single words. Which content folklore is outdated and which content issues still matter.
4 min read