Email deliverability explained
What's behind SPF, DKIM and DMARC, why emails land in spam and which rules the big mailbox providers set – without jargon.
Gmail, Yahoo and Outlook sender requirements: the rules for bulk and newsletter senders
What Gmail, Yahoo and Outlook.com require from senders – from SPF, DKIM and DMARC to one-click unsubscribe. With a checklist for all senders and for newsletters.
7 min read Read moreSPF, DKIM and DMARC explained – with examples and common mistakes
What SPF, DKIM and DMARC do, what the DNS records look like and which mistakes most often send emails to spam. With example records and a step-by-step DMARC rollout.
9 min read Read moreWhy are my emails going to spam? 10 causes and how to fix them
The ten most common reasons why emails land in the spam folder – from missing authentication and blocklists to content and sending behavior. With concrete fixes.
8 min read Read moreHow to read DMARC reports and find every sender using your domain
How to request DMARC aggregate reports (rua), what the XML contains and how to get to p=reject step by step. With a sample report and interpretation guide.
8 min read Read moreReverse DNS (PTR) for mail servers: what it is and how to set it up correctly
Why Gmail rejects emails without a PTR record, what a correct reverse DNS record looks like, who sets it and what to watch out for with IPv6.
6 min read Read moreIP or domain on a blacklist? How to find the cause and get delisted
How to recognize a blocklist listing, what causes it and how removal works at Spamhaus, Barracuda, SpamCop and others.
7 min read Read moreSetting up MTA-STS and TLS-RPT: enforce encrypted email delivery
How MTA-STS prevents emails to your domain from being transmitted unencrypted: DNS record, policy, testing mode, TLS-RPT reports and common mistakes.
7 min read Read moreGoogle Postmaster Tools: how to see what Gmail thinks of your emails
Setting up Google Postmaster Tools, the key metrics such as the spam rate and why data often doesn't appear.
6 min read Read moreAdding SPF, DKIM and DMARC records: the typical mistakes at every DNS provider
Name, type, value, TTL: what to watch out for when adding SPF, DKIM and DMARC records – doubled domain names, long keys, CNAME and waiting times.
6 min read Read more