One-on-one deliverability consultationBook
Compliance guide

Google & Yahoo Sender Requirements

Google and Yahoo now block bulk senders who miss the bar: authentication, one-click unsubscribe and spam rates under 0.3%. Here are the full requirements, how to check your status and the Warmy feature that covers each rule.

  • Gmail, Yahoo & Microsoft
  • Check your status free
  • Fix every rule
Check my DNS freeTalk to an expert

4.9/5 on G2 · Trusted by 7,000+ businesses

Trusted by teams that live in the inbox

01
7,000+

Businesses warming up with Warmy

02
4.9/5

Average rating on G2

03
98%

Average inbox placement reached

04
24/7

Human deliverability support

The checklist

Every rule, in one table

Requirements that apply to all senders, and the extra rules for bulk senders (about 5,000+ messages a day to Gmail).

5,000+

emails a day makes you a bulk sender

< 0.3%

spam complaint rate, never above

2 days

to honor one-click unsubscribes

  • SPF or DKIM authentication

    Every message authenticated by at least one.

    All sendersBulk senders
    SPF Checker →

  • Both SPF and DKIM

    Bulk senders must pass both.

    Bulk senders
    DKIM Checker →

  • DMARC record (p=none minimum)

    Published on your From domain, aligned with SPF or DKIM.

    Bulk senders
    DMARC Checker →

  • Spam rate under 0.3%

    Measured in Google Postmaster Tools. Aim to stay under 0.1%.

    All sendersBulk senders
    Google Postmaster in Warmy →

  • One-click unsubscribe (RFC 8058)

    List-Unsubscribe + List-Unsubscribe-Post headers; honour within 2 days.

    Bulk senders
    Email Header Analyzer →

  • Valid forward and reverse DNS

    Sending IPs need a PTR record that matches.

    All sendersBulk senders
    DNS Record Checker →

  • TLS connection

    Send over an encrypted connection.

    All sendersBulk senders
    Deliverability Test →

  • RFC 5322 formatting

    Correctly formatted messages; no Gmail From-address impersonation.

    All sendersBulk senders
    Email Header Analyzer →

By provider

What each mailbox provider enforces

  • Since February 2024

    Gmail

    SPF, DKIM, DMARC, one-click unsubscribe and a spam rate under 0.3% for bulk senders. Enforcement has tightened steadily, from temporary errors to outright rejection.

  • Since February 2024

    Yahoo

    Matching rules: authentication, DMARC, one-click unsubscribe honoured within two days and low complaint rates.

  • Since May 2025

    Microsoft Outlook

    Outlook.com, Hotmail and Live require SPF, DKIM and DMARC (p=none, aligned) from senders of 5,000+ messages a day. Non-compliant mail is rejected.

Your status

How to check if you're compliant

  1. 1

    Check your DNS records

    Run the DNS Record Checker to confirm SPF, DKIM and DMARC are published and valid.

  2. 2

    Inspect a real email's headers

    Send yourself a campaign and paste the headers into the Email Header Analyzer: look for SPF, DKIM and DMARC pass and the List-Unsubscribe headers.

  3. 3

    Watch your spam rate

    Connect Google Postmaster Tools. Keep user-reported spam under 0.1% and never let it reach 0.3%.

  4. 4

    Test real placement

    Run a deliverability test to see whether Gmail, Yahoo and Outlook put you in the inbox, Promotions or spam.

Google and Yahoo bulk sender requirements in practice

The rules in the table above apply to everyone who sends to Gmail and Yahoo users, with stricter ones for bulk senders. This section covers the details that cause most failed checks: who counts as a bulk sender, how one-click unsubscribe works, how the spam rate is measured and what the rejection codes mean.

Who counts as a bulk sender

Google defines a bulk sender as anyone who has sent close to 5,000 or more messages to personal Gmail accounts in a single day. The count is per primary domain, so mail from news.yourdomain.com and billing.yourdomain.com adds up. The status is permanent: once you cross the line, the bulk rules keep applying even if volume drops later. Yahoo follows the same logic. Microsoft applies its own version for senders of more than 5,000 messages a day to Outlook.com, Hotmail and Live addresses.

One-click unsubscribe (RFC 8058) explained

Marketing and subscribed messages must carry two headers: List-Unsubscribe, with an HTTPS link, and List-Unsubscribe-Post with the value List-Unsubscribe=One-Click. Together they let Gmail and Yahoo show an unsubscribe button that works without opening a web page. You must also keep a visible unsubscribe link in the body and honour requests within two days. Transactional mail such as receipts and password resets doesn't need the header. Most email platforms add both headers automatically, but custom setups often miss the Post header. Our guide on unsubscribe links and deliverability shows a correct example.

Spam complaint rate under 0.3%

The spam rate is the share of your delivered mail that recipients report as spam, as measured in Google Postmaster Tools. Stay below 0.1%, and never reach 0.3%. Above that line, Gmail filters far more of your mail and stops offering mitigation while the rate stays high. Complaints come mostly from people who don't remember signing up, so sudden sends to old segments are the usual cause. See how to lower your spam complaint rate for the full playbook.

Error codes when you don't meet sender requirements

Enforcement has moved from warnings and temporary errors to outright rejection. Gmail returns 550 5.7.26 for unauthenticated mail and 5.7.1 codes for messages it considers likely spam. Microsoft rejects non-compliant bulk mail to its consumer domains with 550 5.7.515. If you see these codes in your bounce logs, start with authentication: SPF, DKIM and a DMARC record aligned with your From domain.

Next step: check your compliance status

Run the free DNS Record Checker to confirm SPF, DKIM, DMARC and MX in one lookup, then send a test through the Email Deliverability Test to see real placement. Warmy connects to Google Postmaster Tools, tracks your spam rate daily and warms up your domain so you stay compliant as volume grows.

Meet every requirement and stay in the inbox. Start a 7-day trial or book a demo with a deliverability expert.

Get a 7-Day TrialBook a Demo
Why Warmy

Everything Deliverability
In One Platform

One platform, one subscription, one team, no add-ons, no extra vendors.

Scale & people

  • 1M+ real mailboxes - The largest warm-up network — genuine Workspace, Microsoft 365 and consumer inboxes.

  • A dedicated success manager - A named expert who owns your placement outcomes, not a ticket queue.

  • 24/7 support, VIP channels - Real people any hour, in your own Slack, WhatsApp or Teams channel.

  • 120+ deliverability specialists - The largest team in the category, dedicated to inbox placement.

  • An in-house research team - Continuous experiments on how Gmail, Outlook and Yahoo filter this month.

  • Recognised experts - Specialists who advise on sender reputation daily — not generalists.

Technology

  • Adeline AI co-pilot - Reads your tests, DNS and warm-up data, then tells you what to fix next.

  • The infrastructure behind other tools - Outreach platforms and ESPs run their warm-up on our API.

  • One loop: test, warm, fix - Placement tests, warm-up, monitoring and fixes in a single platform.

  • 500K+ US seed accounts - Real inboxes across major, corporate and regional providers — mobile included.

  • Monthly seed rotation - Aging mailboxes retire automatically, so your data comes from live inboxes.

  • Automation built in - n8n, Zapier, Make and a documented API — no CSVs, no manual seed files.

Included in every plan

  • Email verification - Clean lists before you send, so bounces never cost you reputation.

  • DMARC tracker - SPF, DKIM and DMARC monitoring with the exact record to change.

  • Deliverability tester - Instant placement, authentication and blacklist check for any sender.

  • Templates AI optimizer - Your campaign scored and rewritten for the inbox before you send.

  • Reputation tracker - Domain and IP reputation with blacklist alerts the moment a signal drops.

  • Google Postmaster built in - Postmaster data beside your warm-up and placement results.

  • Working-hours warm-up - Natural business-hours sending in the recipient’s time zone.

  • A robust API - Every feature available over documented endpoints.

No extra vendors, no add-on fees, no separate contracts.

Loved By Thousands Of Marketers Around The World

The platform’s warmup processes make sure that our cold emails don’t bounce into spam filters. It also makes use of AI behavior tracking as we’re sending which is great for campaigns scaling. It’s also really valuable to be able to track open rates and responses.
Allan Black
Allan BlackSenior Affiliate & Strategic Partnerships Manager
ActualSales

Over 7,000 Businesses Trust Warmy

motion
awesomic
Benchmark International
UserWay, a Level Access company
Quicklizard
Selling.com
YouTEAM
aid
Lusha
pathrise
plivo
adpushup
FAQ

Sender Requirements
Questions, Answered

Since February 2024, Gmail and Yahoo expect every sender to authenticate with SPF or DKIM, use valid forward and reverse DNS, send over TLS and keep spam complaints under 0.3%. Bulk senders must also pass both SPF and DKIM, publish a DMARC record aligned with the From domain, and add one-click unsubscribe to marketing mail, honouring requests within two days.
Get started

Meet Every Requirement.
Warmy Keeps You Compliant And In The Inbox

Get a 7-Day TrialBook a Demo

No Credit Card Required | Cancel Anytime