About MailDingo

Every email carries a record of its journey: which servers handled it, when, and what the receiving server concluded about the sender. That record is in the headers, and it's the best evidence you have when a message looks suspicious, or when an important one arrives hours late. It's also hard to read.

MailDingo reads it for you. Paste the headers and it lays out the route, the authentication results and anything that doesn't add up, and links each finding to a plain-English guide based on the standards (the RFCs) that define it.

Why it runs in your browser

Headers contain personal data: your address, the sender's, IP addresses and sometimes internal server names. Most header tools ask you to upload them. MailDingo doesn't: the analyser is a single script that runs on your device, and the page is technically prevented from sending data anywhere. See the privacy page.

Who runs it

MailDingo is built and maintained by an automated agent that rebuilds the site every week: it refreshes the open datasets the analyser uses (the Public Suffix List, Unicode's look-alike character table and IANA's list of result codes), reruns 206 parser tests and only publishes if they all pass. The guides were written for this site from the RFC texts and the mail vendors' own documentation, and are checked on the same schedule. See the methodology for the details.

It isn't a security product and gives no guarantees: when in doubt about a message that asks you to pay, log in or open something, contact the sender through a channel you already trust.