Mailbox providers · verified 4 Aug 2026
What they actually said. And what they never did.
Nobody outside Google knows how Gmail filters mail, and every page claiming to explain the algorithm is either restating the published guidelines or inventing. So this does the opposite. For each provider: the requirements and numbers it printed, in its own words — and, given the same weight, the things this industry repeats that the provider has never said anywhere.
That last figure is the uncomfortable one and it stays on the page. Google’s help centre and Yahoo’s sender hub print no publication date on the pages that carry their requirements, so none is claimed here. A reference that invents a plausible date to look rigorous has stopped being one.
Gmail
4 stated · 3 never said · 1 removal pathGoogle's consumer mailbox and the Workspace stack behind it. The one everybody means when they say deliverability.
Never said: Gmail weights domain reputation over IP reputation.
Yahoo
5 stated · 2 never said · 1 removal pathYahoo Mail, AOL and the rest of the Yahoo estate, which share one sender policy and one postmaster team.
Never said: There is a safe number of concurrent connections to Yahoo.
Microsoft 365
3 stated · 2 never said · 2 removal pathsThe business mail stack — anything behind *.mail.protection.outlook.com. Not the same service as Outlook.com, and not the same delisting path.
Never said: The delist portal handles every Microsoft block.
Outlook.com
2 stated · 1 never said · 1 removal pathThe consumer service — outlook.com, hotmail.com, live.com, msn.com. Shares a filtering heritage with Microsoft 365 and does not share its delisting path.
Never said: SNDS shows you your Outlook.com reputation.
Apple iCloud Mail
2 stated · 1 never said · 1 removal pathicloud.com, me.com and mac.com. Small share, loud effect: Apple's client is where Mail Privacy Protection and AI summaries change what your numbers mean.
Never said: Apple Mail Privacy Protection only affects Apple Mail users' opens.
Opened, with nothing to publish
These were looked at during this review and produced nothing that met the bar. The reason matters more than the absence, so each one says why. A delisting path published from memory is how a reference gets somebody’s mail permanently blocked.
- Proton MailPublishes user-facing help and a security policy, but no sender guidance, no thresholds and no delisting path we could cite. Nothing to put in a threshold column.
- GMX and Web.deUnited Internet operates a postmaster contact, and the sender documentation behind it is not published as a stable, dateable page in English or German. Watched.
- Mail.ru, Yandex, QQ, NetEase, Naver, DaumEach runs a real postmaster function with real delisting. None has been read against this corpus's bar yet, and publishing a delisting path from memory is precisely how a reference gets somebody's mail permanently blocked.
- Comcast, Cox, Charter and the US cable ISPsMostly delegate consumer mail to third-party filters now, so the question is usually which filter rather than which ISP. Not yet traced to a citable page per operator.
A provider missing, a quote wrong, or a delisting path that has moved? corrections@emailrules.today. How a claim gets onto this site at all is on methodology; the same discipline applied to blocklists is the census. Last verified 4 Aug 2026.