Gmail, Yahoo and Microsoft now expect senders to meet a set of basic requirements: authenticated mail, easy unsubscribes and low complaint rates. This check asks twelve questions about those requirements and the habits behind them: how you handle bounces and unengaged contacts, where your contacts came from, how steady your volume is, and whether cold and transactional email are kept apart from marketing. Each question takes Yes, No or Not sure.
This is a questionnaire. It does not look up your DNS records or connect to your email platform, so it can only reflect what you tell it. If you’re not sure whether SPF, DKIM or DMARC are set up, choose “Not sure”; that answer is useful in itself.
Run the check
How to read the result
The top of the result is the percentage of questions you answered “Yes”, with a short label: Fix the critical items first if any critical question got a No or Not sure, Some important gaps if the remaining misses are in the important group, and Fundamentals in place otherwise. Below it, every question you didn’t answer “Yes” is listed with a one-line reason, grouped under three headings:
- Critical: SPF, DKIM signed with your own domain, a published DMARC record, one-click unsubscribe, and contacts that all opted in.
- Important: DMARC alignment, complaint-rate monitoring, bounce suppression, and keeping cold outreach on separate domains.
- Worth fixing: a sunset process for unengaged contacts, steady sending volume, and transactional email separated from marketing.
“Not sure” is listed alongside “No”, because an unknown setting carries the same risk until someone checks it.
Authentication questions sit mostly in the critical group because they’re the ones mailbox providers now enforce directly. Microsoft, for example, began filtering and rejecting mail from high-volume senders to Outlook.com, Hotmail.com and Live.com addresses that doesn’t meet its SPF, DKIM and DMARC requirements in 2025. If you answered “No” or “Not sure” here, check your records with our SPF, DKIM and DMARC guides.
Unsubscribe handling covers one-click unsubscribe (the List-Unsubscribe headers Google requires on marketing messages from bulk senders) and how quickly requests are processed. Google asks for opt-outs to be honored within two days.
Complaint monitoring asks whether anyone actually looks at spam complaint rates, for example in Google Postmaster Tools, and whether they stay below 0.1%. It’s common for a team to meet every technical requirement and still learn about a problem only when sales drop, because the one number that showed it early wasn’t on anyone’s weekly list.
List hygiene and sending patterns are about behavior: sending to people who haven’t engaged in a long time, importing old lists, or sending in sudden large bursts. These are usually the root cause when authentication is fine but placement is poor. The last two questions, about separate domains for cold outreach and a separate stream for receipts and password resets, decide how far a reputation problem in one kind of email can spread to the others. Our guides to email list hygiene and sender reputation go into each.
A realistic example: a store answers yes to every authentication question and has one-click unsubscribe through its platform. But it sends every campaign to its full list, including people who haven’t opened or clicked in two years, and no one on the team has opened Postmaster Tools. Its score looks respectable, yet complaint monitoring appears under Important and the sunset question under Worth fixing. Those two answers explain more about its declining open rates than any DNS record would.
What this check can’t tell you
It can’t confirm your records are valid, see your actual complaint or bounce rates, or test where your mail lands. A critical item is a reason to look closer, not a diagnosis, and a perfect score doesn’t guarantee inbox placement; it removes the most common causes of problems. For outbound and cold email specifically, the cold email deliverability guide covers the extra factors involved.