Guides
The email problems everyone hits, explained in plain English
Every guide pairs the explanation with the fix — and the free check that verifies it worked.
Fix-it guides
SPF PermError: too many DNS lookups — how to fix it
SPF has a hard limit of 10 DNS lookups. Go over it and receivers see a PermError, which DMARC treats as a fail. Here's how to count your lookups and get back under the limit.
Multiple SPF records: why it breaks everything and how to merge them
Two SPF records don't add up — they cancel out. Receivers treat multiple SPF records as a PermError, i.e. a fail. Here's how to merge them into one record correctly.
DKIM "body hash did not verify" — what it means and how to fix it
The 'body hash did not verify' DKIM failure means the message changed after it was signed. Here's what modifies email in transit and how to fix each cause.
Gmail error 550 5.7.26 "unauthenticated email" — how to fix it
Gmail bounces with 550 5.7.26 mean your mail failed both SPF and DKIM checks. Here's exactly what Gmail requires and the records to publish to make the bounces stop.
Explainers
SPF ~all vs -all: softfail vs hardfail, explained
The last term of your SPF record decides what happens to mail from servers you didn't authorize. Here's the real-world difference between ~all and -all in 2026, and which one to publish.
DMARC p=none vs quarantine vs reject: which policy should you use?
Your DMARC p= tag decides what happens to mail that fails authentication: nothing, spam folder, or refused. Here's what each policy actually does and when to move up.
DMARC alignment: why SPF and DKIM pass but DMARC still fails
SPF and DKIM can both pass while DMARC fails. The missing piece is alignment: the authenticated domain has to match the From address the recipient sees. Here's how it works and how to fix it.
How to read a DMARC report (with a real example)
DMARC aggregate reports arrive as gzipped XML that no human enjoys. Here's what each field means, how to spot spoofing vs misconfiguration, and how to stop reading XML entirely.
Why your emails go to spam: 8 causes, in order of likelihood
Emails landing in spam is a symptom with a short list of causes. Here are the eight that account for nearly every case, ordered by how often they're the culprit, each with its fix.