{
 "name": "Email sender requirements",
 "description": "Gmail, Yahoo Mail and Outlook.com sender rules, each cell tied to quotes from the provider's pages.",
 "license": "https://creativecommons.org/licenses/by/4.0/",
 "rights": "MyIPScan's work under CC BY 4.0; quoted text belongs to its source.",
 "attribution": "MyIPScan (https://myipscan.net/tools/email-security/sender-requirements/); quoted evidence belongs to its source",
 "page": "https://myipscan.net/tools/email-security/sender-requirements/",
 "url": "https://myipscan.net/tools/email-security/sender-requirements.json",
 "dateModified": "2026-10-21",
 "records": 15,
 "data": {
  "checked": "2026-10-21",
  "facts": [
   {
    "id": "f00",
    "provider": "gmail",
    "requirement": "effective date",
    "applies_to": "all senders",
    "evidence": "Starting February 1, 2024, all email senders who send email to Gmail accounts must meet",
    "source_url": "https://support.google.com/mail/answer/81126?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f01",
    "provider": "gmail",
    "requirement": "effective date",
    "applies_to": "bulk senders",
    "evidence": "Starting February 2024, Gmail requires the following for senders who send 5,000 or more",
    "source_url": "https://support.google.com/mail/answer/14229414?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f02",
    "provider": "gmail",
    "requirement": "effective date",
    "applies_to": "bulk senders",
    "evidence": "have until June 1, 2024 to implement one-click unsubscribe in all commercial, promotional messages",
    "source_url": "https://support.google.com/mail/answer/14229414?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f03",
    "provider": "gmail",
    "requirement": "enforcement escalation (November 2025)",
    "applies_to": "all senders",
    "evidence": "Starting November 2025, Gmail is ramping up its enforcement on non-compliant traffic.",
    "source_url": "https://support.google.com/mail/answer/14229414?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f04",
    "provider": "gmail",
    "requirement": "scope: recipient domains",
    "applies_to": "all senders",
    "evidence": "A personal Gmail account is an account that ends in @gmail.com or @googlemail.com.",
    "source_url": "https://support.google.com/mail/answer/81126?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f05",
    "provider": "gmail",
    "requirement": "scope: Workspace recipients excluded",
    "applies_to": "all senders",
    "evidence": "Sender requirements and Google enforcement apply only when sending email to personal Gmail accounts.",
    "source_url": "https://support.google.com/mail/answer/14229414?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f06",
    "provider": "gmail",
    "requirement": "SPF or DKIM for all senders",
    "applies_to": "all senders",
    "evidence": "Set up SPF or DKIM email authentication for your sending domains.",
    "source_url": "https://support.google.com/mail/answer/81126?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f07",
    "provider": "gmail",
    "requirement": "DKIM key length",
    "applies_to": "all senders",
    "evidence": "Sending to personal Gmail accounts requires a DKIM key of 1024 bits or longer.",
    "source_url": "https://support.google.com/mail/answer/81126?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f08",
    "provider": "gmail",
    "requirement": "PTR record",
    "applies_to": "all senders",
    "evidence": "Ensure that sending domains or IPs have valid forward and reverse DNS records",
    "source_url": "https://support.google.com/mail/answer/81126?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f09",
    "provider": "gmail",
    "requirement": "TLS",
    "applies_to": "all senders",
    "evidence": "Use a TLS connection for transmitting email.",
    "source_url": "https://support.google.com/mail/answer/81126?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f10",
    "provider": "gmail",
    "requirement": "spam rate threshold",
    "applies_to": "all senders",
    "evidence": "keep your user-reported spam rate below 0.1% and prevent it from reaching 0.3% or higher",
    "source_url": "https://support.google.com/mail/answer/14229414?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f11",
    "provider": "gmail",
    "requirement": "spam rate threshold: mitigation eligibility",
    "applies_to": "bulk senders",
    "evidence": "bulk senders with a user-reported spam rate greater than 0.3% will be ineligible for",
    "source_url": "https://support.google.com/mail/answer/14229414?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f12",
    "provider": "gmail",
    "requirement": "RFC 5322 message format",
    "applies_to": "all senders",
    "evidence": "Format messages according to the Internet Message Format standard",
    "source_url": "https://support.google.com/mail/answer/81126?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f13",
    "provider": "gmail",
    "requirement": "no Gmail From: impersonation",
    "applies_to": "all senders",
    "evidence": "impersonating Gmail From: headers might impact your email delivery",
    "source_url": "https://support.google.com/mail/answer/81126?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f14",
    "provider": "gmail",
    "requirement": "volume threshold that defines a bulk sender",
    "applies_to": "bulk senders",
    "evidence": "sends close to 5,000 messages or more to personal Gmail accounts within a 24-hour period",
    "source_url": "https://support.google.com/mail/answer/14229414?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f15",
    "provider": "gmail",
    "requirement": "bulk threshold counted per primary domain",
    "applies_to": "bulk senders",
    "evidence": "Messages sent from the same primary domain count toward the 5,000 limit.",
    "source_url": "https://support.google.com/mail/answer/14229414?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f16",
    "provider": "gmail",
    "requirement": "bulk status is permanent",
    "applies_to": "bulk senders",
    "evidence": "Senders who meet the above criteria at least once are permanently considered bulk senders.",
    "source_url": "https://support.google.com/mail/answer/14229414?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f17",
    "provider": "gmail",
    "requirement": "SPF and DKIM and DMARC for bulk senders",
    "applies_to": "bulk senders",
    "evidence": "Set up SPF and DKIM email authentication for your domain.",
    "source_url": "https://support.google.com/mail/answer/81126?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f18",
    "provider": "gmail",
    "requirement": "DMARC record for bulk senders",
    "applies_to": "bulk senders",
    "evidence": "Set up DMARC email authentication for your sending domain.",
    "source_url": "https://support.google.com/mail/answer/81126?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f19",
    "provider": "gmail",
    "requirement": "DMARC policy at least p=none",
    "applies_to": "bulk senders",
    "evidence": "DMARC record is missing (Minimum policy of none, p=none)",
    "source_url": "https://support.google.com/mail/answer/14229414?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f20",
    "provider": "gmail",
    "requirement": "alignment",
    "applies_to": "bulk senders",
    "evidence": "header must be aligned with either the SPF domain or the DKIM domain",
    "source_url": "https://support.google.com/mail/answer/81126?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f21",
    "provider": "gmail",
    "requirement": "one-click unsubscribe",
    "applies_to": "bulk senders",
    "evidence": "Marketing messages and subscribed messages must support one-click unsubscribe",
    "source_url": "https://support.google.com/mail/answer/81126?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f22",
    "provider": "gmail",
    "requirement": "one-click unsubscribe: promotional mail only",
    "applies_to": "bulk senders",
    "evidence": "One-click unsubscribe is required only for marketing and promotional messages.",
    "source_url": "https://support.google.com/mail/answer/14229414?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f23",
    "provider": "gmail",
    "requirement": "one-click unsubscribe: HTTPS header required, mailto not enough",
    "applies_to": "bulk senders",
    "evidence": "include one HTTPS URL in the List-unsubscribe: header",
    "source_url": "https://support.google.com/mail/answer/14229414?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f24",
    "provider": "gmail",
    "requirement": "visible unsubscribe link in body",
    "applies_to": "bulk senders",
    "evidence": "include a clearly visible unsubscribe link in the message body",
    "source_url": "https://support.google.com/mail/answer/81126?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f25",
    "provider": "gmail",
    "requirement": "unsubscribe processing time",
    "applies_to": "bulk senders",
    "evidence": "we recommend that you fulfill unsubscribe requests within 48 hours",
    "source_url": "https://support.google.com/mail/answer/14229414?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f26",
    "provider": "yahoo",
    "requirement": "effective date",
    "applies_to": "all senders",
    "evidence": "Beginning in February 2024, enforcement of the following sending standards will take effect.",
    "source_url": "https://senders.yahooinc.com/best-practices/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f27",
    "provider": "yahoo",
    "requirement": "effective date",
    "applies_to": "bulk senders",
    "evidence": "Enforcement of the List-Unsubscribe policy will begin in June 2024.",
    "source_url": "https://senders.yahooinc.com/faqs/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f28",
    "provider": "yahoo",
    "requirement": "scope: recipient domains",
    "applies_to": "all senders",
    "evidence": "These requirements apply for all domains and consumer email brands hosted by Yahoo Mail.",
    "source_url": "https://senders.yahooinc.com/faqs/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f29",
    "provider": "yahoo",
    "requirement": "SPF or DKIM for all senders",
    "applies_to": "all senders",
    "evidence": "Implement SPF or DKIM at a minimum",
    "source_url": "https://senders.yahooinc.com/best-practices/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f30",
    "provider": "yahoo",
    "requirement": "DKIM key length",
    "applies_to": "all senders",
    "evidence": "We require a DKIM key length of 1024 bits or greater",
    "source_url": "https://senders.yahooinc.com/faqs/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f31",
    "provider": "yahoo",
    "requirement": "spam rate threshold",
    "applies_to": "all senders",
    "evidence": "Keep your spam rate below 0.3%",
    "source_url": "https://senders.yahooinc.com/best-practices/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f32",
    "provider": "yahoo",
    "requirement": "spam rate: how it is calculated",
    "applies_to": "bulk senders",
    "evidence": "Spam rate is calculated in our system based on mail delivered to the inbox",
    "source_url": "https://senders.yahooinc.com/best-practices/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f33",
    "provider": "yahoo",
    "requirement": "PTR record",
    "applies_to": "all senders",
    "evidence": "Have a valid forward and reverse DNS record for your sending IPs",
    "source_url": "https://senders.yahooinc.com/best-practices/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f34",
    "provider": "yahoo",
    "requirement": "RFC 5321 and 5322 compliance",
    "applies_to": "all senders",
    "evidence": "Comply with RFCs",
    "source_url": "https://senders.yahooinc.com/best-practices/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f35",
    "provider": "yahoo",
    "requirement": "SPF and DKIM and DMARC for bulk senders",
    "applies_to": "bulk senders",
    "evidence": "Implement both SPF",
    "source_url": "https://senders.yahooinc.com/best-practices/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f36",
    "provider": "yahoo",
    "requirement": "DMARC policy at least p=none",
    "applies_to": "bulk senders",
    "evidence": "Publish a valid DMARC policy with at least p=none",
    "source_url": "https://senders.yahooinc.com/best-practices/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f37",
    "provider": "yahoo",
    "requirement": "alignment",
    "applies_to": "bulk senders",
    "evidence": "header is aligned with either the SPF domain or the DKIM domain",
    "source_url": "https://senders.yahooinc.com/best-practices/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f38",
    "provider": "yahoo",
    "requirement": "one-click unsubscribe",
    "applies_to": "bulk senders",
    "evidence": "Implement a functioning list-unsubscribe header, which supports one-click unsubscribe for marketing and subscribed messages",
    "source_url": "https://senders.yahooinc.com/best-practices/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f39",
    "provider": "yahoo",
    "requirement": "one-click unsubscribe: mailto accepted",
    "applies_to": "bulk senders",
    "evidence": "The mail-to: method is acceptable",
    "source_url": "https://senders.yahooinc.com/best-practices/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f40",
    "provider": "yahoo",
    "requirement": "one-click unsubscribe: promotional mail only",
    "applies_to": "bulk senders",
    "evidence": "one-click unsubscribe is only required for promotional/marketing messages",
    "source_url": "https://senders.yahooinc.com/faqs/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f41",
    "provider": "yahoo",
    "requirement": "visible unsubscribe link in body",
    "applies_to": "bulk senders",
    "evidence": "Have a clearly visible unsubscribe link in the email body",
    "source_url": "https://senders.yahooinc.com/best-practices/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f42",
    "provider": "yahoo",
    "requirement": "unsubscribe processing time",
    "applies_to": "bulk senders",
    "evidence": "Honor unsubscribes within 2 days",
    "source_url": "https://senders.yahooinc.com/best-practices/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f43",
    "provider": "yahoo",
    "requirement": "volume threshold that defines a bulk sender",
    "applies_to": "bulk senders",
    "evidence": "We will not specify a volume threshold.",
    "source_url": "https://senders.yahooinc.com/faqs/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f44",
    "provider": "yahoo",
    "requirement": "bulk sender: unit of measurement",
    "applies_to": "bulk senders",
    "evidence": "is viewed at the authenticated domain or From header domain level",
    "source_url": "https://senders.yahooinc.com/faqs/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f45",
    "provider": "yahoo",
    "requirement": "enforcement action",
    "applies_to": "all senders",
    "evidence": "your mail may be sent to the spam folder or rejected",
    "source_url": "https://senders.yahooinc.com/faqs/",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f48",
    "provider": "outlook",
    "requirement": "volume threshold that defines a bulk sender",
    "applies_to": "bulk senders",
    "evidence": "or more email messages to Microsoft consumer email services.",
    "source_url": "https://support.microsoft.com/en-us/outlook/fix-ndr-error-550-5-7-515-in-outlook-com",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f49",
    "provider": "outlook",
    "requirement": "threshold reached: applies to all mail from the domain",
    "applies_to": "bulk senders",
    "evidence": "we expect all messages from senders in the domain to meet",
    "source_url": "https://support.microsoft.com/en-us/outlook/fix-ndr-error-550-5-7-515-in-outlook-com",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f52",
    "provider": "outlook",
    "requirement": "SPF and DKIM and DMARC for bulk senders",
    "applies_to": "bulk senders",
    "evidence": "Both SPF and DKIM checks must pass.",
    "source_url": "https://support.microsoft.com/en-us/outlook/fix-ndr-error-550-5-7-515-in-outlook-com",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f54",
    "provider": "outlook",
    "requirement": "alignment",
    "applies_to": "bulk senders",
    "evidence": "The SPF and/or DKIM record (at least one) must align with",
    "source_url": "https://support.microsoft.com/en-us/outlook/fix-ndr-error-550-5-7-515-in-outlook-com",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f63",
    "provider": "outlook",
    "requirement": "scope: recipient domains",
    "applies_to": "bulk senders",
    "evidence": "send email to Outlook.com and related Microsoft consumer email services (Hotmail, Live.com, MSN, etc.)",
    "source_url": "https://support.microsoft.com/en-us/outlook/fix-ndr-error-550-5-7-515-in-outlook-com",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f64",
    "provider": "outlook",
    "requirement": "enforcement action",
    "applies_to": "bulk senders",
    "evidence": "your message was rejected because the domain in your 5322.From email address",
    "source_url": "https://support.microsoft.com/en-us/outlook/fix-ndr-error-550-5-7-515-in-outlook-com",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f65",
    "provider": "outlook",
    "requirement": "DMARC policy",
    "applies_to": "bulk senders",
    "evidence": "The DMARC TXT record contains a valid DMARC policy",
    "source_url": "https://support.microsoft.com/en-us/outlook/fix-ndr-error-550-5-7-515-in-outlook-com",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f66",
    "provider": "outlook",
    "requirement": "DMARC record for bulk senders",
    "applies_to": "bulk senders",
    "evidence": "Publish a DMARC record for the domain",
    "source_url": "https://support.microsoft.com/en-us/outlook/fix-ndr-error-550-5-7-515-in-outlook-com",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f67",
    "provider": "outlook",
    "requirement": "enforcement action",
    "applies_to": "bulk senders",
    "evidence": "550 5.7.515 Access denied, sending domain",
    "source_url": "https://support.microsoft.com/en-us/outlook/fix-ndr-error-550-5-7-515-in-outlook-com",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f70",
    "provider": "gmail",
    "requirement": "enforcement action",
    "applies_to": "all senders",
    "evidence": "will experience disruptions, including temporary and permanent rejections",
    "source_url": "https://support.google.com/mail/answer/14229414?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f71",
    "provider": "gmail",
    "requirement": "enforcement action",
    "applies_to": "all senders",
    "evidence": "Temporary or Permanent Failure codes, or spam foldering",
    "source_url": "https://support.google.com/mail/answer/14229414?hl=en",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f72",
    "provider": "outlook",
    "requirement": "effective date",
    "applies_to": "all senders",
    "evidence": "Starting May 5th, 2025, Outlook.com is enforcing stricter email authentication standards",
    "source_url": "https://sendersupport.olc.protection.outlook.com/pm/policies.aspx",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f73",
    "provider": "outlook",
    "requirement": "PTR record",
    "applies_to": "all senders",
    "evidence": "Email servers must have valid reverse DNS records.",
    "source_url": "https://substrate.office.com/ip-domain-management-snds/Postmaster/Policies",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f74",
    "provider": "outlook",
    "requirement": "RFC compliance",
    "applies_to": "all senders",
    "evidence": "including RFC 2821, RFC 2822, and others",
    "source_url": "https://substrate.office.com/ip-domain-management-snds/Postmaster/Policies",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f75",
    "provider": "outlook",
    "requirement": "unsubscribe mechanism",
    "applies_to": "all senders",
    "evidence": "must be clearly documented and easy for recipients to find and use",
    "source_url": "https://substrate.office.com/ip-domain-management-snds/Postmaster/Policies",
    "verified_at": "2026-10-21"
   },
   {
    "id": "f76",
    "provider": "outlook",
    "requirement": "volume threshold that defines a bulk sender",
    "applies_to": "all senders",
    "evidence": "for domains sending over 5,000 emails per day",
    "source_url": "https://sendersupport.olc.protection.outlook.com/pm/policies.aspx",
    "verified_at": "2026-10-21"
   }
  ],
  "matrix": [
   {
    "row": "Who counts as a bulk sender",
    "applies": "definition",
    "cells": {
     "gmail": {
      "text": "Close to 5,000 or more messages a day to personal Gmail accounts, counted per primary domain. Once reached, always bulk.",
      "facts": [
       "f14",
       "f15",
       "f16"
      ]
     },
     "yahoo": {
      "text": "No number published: a “significant volume”, judged per authenticated or From domain.",
      "facts": [
       "f43",
       "f44"
      ]
     },
     "outlook": {
      "text": "5,000 or more messages a day to Outlook.com, Hotmail, Live.com, MSN and other Microsoft consumer addresses, all from one From domain.",
      "facts": [
       "f48",
       "f63",
       "f76"
      ]
     }
    }
   },
   {
    "row": "SPF or DKIM",
    "applies": "all senders",
    "cells": {
     "gmail": {
      "text": "Required.",
      "facts": [
       "f06"
      ]
     },
     "yahoo": {
      "text": "Required.",
      "facts": [
       "f29"
      ]
     },
     "outlook": {
      "text": "Not stated for senders under the bulk line.",
      "facts": []
     }
    }
   },
   {
    "row": "SPF and DKIM and DMARC",
    "applies": "bulk senders",
    "cells": {
     "gmail": {
      "text": "All three required.",
      "facts": [
       "f17",
       "f18"
      ]
     },
     "yahoo": {
      "text": "All three required.",
      "facts": [
       "f35",
       "f36"
      ]
     },
     "outlook": {
      "text": "SPF and DKIM must pass, and a DMARC record must be published and pass.",
      "facts": [
       "f52",
       "f66"
      ]
     }
    }
   },
   {
    "row": "DMARC policy",
    "applies": "bulk senders",
    "cells": {
     "gmail": {
      "text": "At least p=none.",
      "facts": [
       "f19"
      ]
     },
     "yahoo": {
      "text": "At least p=none, and it must pass.",
      "facts": [
       "f36"
      ]
     },
     "outlook": {
      "text": "Any valid policy, p=none included.",
      "facts": [
       "f65"
      ]
     }
    }
   },
   {
    "row": "Alignment",
    "applies": "bulk senders",
    "cells": {
     "gmail": {
      "text": "From: domain aligned with the SPF or the DKIM domain.",
      "facts": [
       "f20"
      ]
     },
     "yahoo": {
      "text": "From: domain aligned with the SPF or the DKIM domain; relaxed is fine.",
      "facts": [
       "f37"
      ]
     },
     "outlook": {
      "text": "At least one of SPF or DKIM aligned with the From: domain.",
      "facts": [
       "f54"
      ]
     }
    }
   },
   {
    "row": "DKIM key length",
    "applies": "all senders",
    "cells": {
     "gmail": {
      "text": "1024 bits or longer; 2048 recommended.",
      "facts": [
       "f07"
      ]
     },
     "yahoo": {
      "text": "1024 bits or longer; 2048 recommended.",
      "facts": [
       "f30"
      ]
     },
     "outlook": {
      "text": "Not stated.",
      "facts": []
     }
    }
   },
   {
    "row": "Reverse DNS (PTR)",
    "applies": "all senders",
    "cells": {
     "gmail": {
      "text": "Valid forward and reverse DNS required.",
      "facts": [
       "f08"
      ]
     },
     "yahoo": {
      "text": "Valid forward and reverse DNS required.",
      "facts": [
       "f33"
      ]
     },
     "outlook": {
      "text": "Required by Outlook.com’s sender policy for every sending server.",
      "facts": [
       "f73"
      ]
     }
    }
   },
   {
    "row": "TLS",
    "applies": "all senders",
    "cells": {
     "gmail": {
      "text": "Required.",
      "facts": [
       "f09"
      ]
     },
     "yahoo": {
      "text": "Not stated.",
      "facts": []
     },
     "outlook": {
      "text": "Not stated.",
      "facts": []
     }
    }
   },
   {
    "row": "Spam complaint rate",
    "applies": "all senders",
    "cells": {
     "gmail": {
      "text": "Below 0.3%, aim for below 0.1% (Postmaster Tools).",
      "facts": [
       "f10",
       "f11"
      ]
     },
     "yahoo": {
      "text": "Below 0.3%, counted on mail delivered to the inbox.",
      "facts": [
       "f31",
       "f32"
      ]
     },
     "outlook": {
      "text": "Not stated.",
      "facts": []
     }
    }
   },
   {
    "row": "One-click unsubscribe",
    "applies": "bulk marketing mail",
    "cells": {
     "gmail": {
      "text": "Required (RFC 8058 List-Unsubscribe with an HTTPS URL; mailto alone does not count).",
      "facts": [
       "f21",
       "f22",
       "f23"
      ]
     },
     "yahoo": {
      "text": "Required; RFC 8058 POST recommended, mailto accepted.",
      "facts": [
       "f38",
       "f39",
       "f40"
      ]
     },
     "outlook": {
      "text": "No one-click rule stated; Outlook.com’s sender policy requires an unsubscribe that is clearly documented and easy to find.",
      "facts": [
       "f75"
      ]
     }
    }
   },
   {
    "row": "Visible unsubscribe link",
    "applies": "bulk marketing mail",
    "cells": {
     "gmail": {
      "text": "Required in the message body.",
      "facts": [
       "f24"
      ]
     },
     "yahoo": {
      "text": "Required in the message body.",
      "facts": [
       "f41"
      ]
     },
     "outlook": {
      "text": "An unsubscribe that is easy to find, under Outlook.com’s sender policy.",
      "facts": [
       "f75"
      ]
     }
    }
   },
   {
    "row": "Honour unsubscribes within",
    "applies": "bulk senders",
    "cells": {
     "gmail": {
      "text": "48 hours.",
      "facts": [
       "f25"
      ]
     },
     "yahoo": {
      "text": "2 days.",
      "facts": [
       "f42"
      ]
     },
     "outlook": {
      "text": "Not stated.",
      "facts": []
     }
    }
   },
   {
    "row": "Message format",
    "applies": "all senders",
    "cells": {
     "gmail": {
      "text": "RFC 5322.",
      "facts": [
       "f12"
      ]
     },
     "yahoo": {
      "text": "RFC 5321 and RFC 5322.",
      "facts": [
       "f34"
      ]
     },
     "outlook": {
      "text": "IETF standards; Outlook.com’s policy names RFC 2821 and 2822, since replaced by 5321 and 5322.",
      "facts": [
       "f74"
      ]
     }
    }
   },
   {
    "row": "What happens if you miss them",
    "applies": "enforcement",
    "cells": {
     "gmail": {
      "text": "Rejection (temporary or permanent) or the spam folder; enforcement stepped up in November 2025. A spam rate over 0.3% or a missing DMARC record also costs delivery support.",
      "facts": [
       "f03",
       "f70",
       "f71",
       "f11",
       "f19"
      ]
     },
     "yahoo": {
      "text": "Spam folder or rejection with an error code.",
      "facts": [
       "f45"
      ]
     },
     "outlook": {
      "text": "Rejected with 550 5.7.515 Access denied.",
      "facts": [
       "f67",
       "f64"
      ]
     }
    }
   },
   {
    "row": "In force since",
    "applies": "dates",
    "cells": {
     "gmail": {
      "text": "1 February 2024; one-click unsubscribe from 1 June 2024.",
      "facts": [
       "f00",
       "f01",
       "f02"
      ]
     },
     "yahoo": {
      "text": "February 2024; one-click unsubscribe from June 2024.",
      "facts": [
       "f26",
       "f27"
      ]
     },
     "outlook": {
      "text": "5 May 2025.",
      "facts": [
       "f72"
      ]
     }
    }
   }
  ],
  "not_stated_where": {
   "outlook": [
    "https://sendersupport.olc.protection.outlook.com/pm/policies.aspx",
    "https://substrate.office.com/ip-domain-management-snds/Postmaster/Policies",
    "https://support.microsoft.com/en-us/outlook/fix-ndr-error-550-5-7-515-in-outlook-com"
   ],
   "yahoo": [
    "https://senders.yahooinc.com/best-practices/",
    "https://senders.yahooinc.com/faqs/"
   ]
  }
 }
}