Pre-flight checklist
Eight things to do before your very first send.
Skip any one of these and the others cannot save you. Reputation is a chain.
Flight School · Free on every plan
Getting into the inbox.
Flight School is the free training and pre-flight deck inside Trailblaze Data — training and pre-flight checks for people who send email. Every account, free, pay-as-you-go or monthly, gets the same Flight School: eight short Ground School lessons and live pre-flight checks against public DNS and public blocklists.
Ground SchoolEight short lessons for
Eight short lessons for
your first send.
Whether you’re an email pro or just beginning, it’s got to be done right! Five minutes each. No homework. The full lessons open when you create your free account.
Reading your health check
What each row means, in plain words, and what to do about it.
SPF · DKIM · DMARC · MX · Reverse DNS · Blacklist, row by row.
Warm-up & sending limits
How to grow volume without burning the domain.
A new domain has no reputation. Volume is how you earn one, and how you lose one.
Cold email that lands
Subject lines, length, links and the one ask — the shape providers and people both like.
Providers judge the shape of a message before a human reads a word of it.
Bounce code analyzer
What that rejection message actually means.
A 4 means try later, a 5 means never.
Getting off a blacklist
Stop, find the cause, fix it, then ask. In that order.
Being listed is not a verdict on you. Staying listed is.
Suppression & keyword rules
How the do-not-contact list and keyword rules work together.
Two different jobs, often confused.
What to do with replies
Out-of-office, “not interested”, “who are you” — each one has a right move.
Every reply is data, even the rude ones.
Pre-flight toolsLive checks before
Live checks before
you press send.
Real records, real verdicts, and a plain-English fix next to anything red or amber. All checks read public DNS only; nothing is sent to the domain and no mail is delivered. Ten checks an hour per account.
Blacklist checker
Is this domain or IP on any of the public blocklists we query?
Checks the domain and the addresses its mail servers use against 37 public blocklists, and lists every hit with a removal link.
SPF & DKIM tester
Are the two records that prove your mail is yours in place?
Reads the SPF record and probes common DKIM selectors, then shows the record found and the fix if it’s missing or weak.
DMARC checker
Have you told providers what to do when a check fails?
Reads _dmarc.yourdomain and explains p=none vs quarantine vs reject.
rDNS tester
Does the address resolve back to a name?
PTR lookup for an IP, or the web host’s IP for a domain.
Full health check
All six rows at once — the same check Deliverability runs.
SPF · DKIM · DMARC · MX · reverse DNS · blacklist, with evidence and a fix per row and a “N to fix / Looking good” verdict.
Make sure your list is cleaned with Trailblaze Data
Check a list, or a single address, against the live engine.
Create your account to start. 500 free Miles when you sign up.
Flight School
Included on every plan.
500 free Miles for verification when you sign up. Sign up today to get your free full access.