Why this matters to a small sender
Most small businesses send through an email platform, and the platform handles much of this. But the platform cannot publish DNS records for your domain, choose your From address, or stop you mailing a stale list. When Gmail or Yahoo filters your newsletter, the fix usually sits in one of the items below. Use this as a checklist, then confirm each item in your platform's documentation.
Requirements for every sender to Gmail
Google's sender guidelines list these for all senders to personal Gmail accounts. [1]
- Set up SPF or DKIM for your sending domain.
- Ensure sending domains or IPs have valid forward and reverse DNS (PTR records).
- Use a TLS connection for transmitting email.
- Keep spam rates reported in Postmaster Tools below 0.3%.
- Format messages according to RFC 5322 and do not impersonate Gmail From: headers.
Extra requirements for bulk senders
Google's FAQ defines a bulk sender as one that sends close to 5,000 messages or more to personal Gmail accounts within 24 hours, counting messages from the same primary domain, and says senders who meet that once are permanently considered bulk senders. [2] For them, Google requires both SPF and DKIM, a DMARC record (the policy can be none), alignment between the From: domain and the SPF or DKIM domain, and one-click unsubscribe plus a clearly visible unsubscribe link for marketing and subscribed messages. [1]
| Requirement | Gmail, all senders | Gmail, bulk senders | Yahoo |
|---|---|---|---|
| Authentication | SPF or DKIM [1] | SPF and DKIM [1] | SPF or DKIM minimum; bulk: both [3] |
| DMARC | Not required [1] | Required; p=none allowed [1] | Bulk: valid policy, at least p=none, and DMARC must pass [3] |
| From-domain alignment | Not listed [1] | Required for direct mail [1] | DMARC must pass [3] |
| One-click unsubscribe | Not required [1] | Required for marketing/subscribed mail [1] | Bulk: list-unsubscribe header supporting one-click; RFC 8058 POST highly recommended [3] |
| Unsubscribe timing | Not stated [1] | Google recommends within 48 hours [2] | Honor within 2 days [3] |
| Spam rate | Below 0.3% [1] | Below 0.3% [1] | Below 0.3% [3] |
The spam-rate line in practice
Google's FAQ says spam rate is calculated daily and asks senders to keep it below 0.1% and to prevent it ever reaching 0.3% or higher. Bulk senders above 0.3% are ineligible for mitigation until their rate stays below 0.3% for 7 consecutive days. [2]
Hypothetical scale check: on a send that reaches 2,000 Gmail inboxes, 0.3% is 6 spam reports. That is why mailing people who forgot they subscribed is the fastest way into trouble. Confirmed opt-in and regular cleanup of inactive subscribers lower this risk.
A 30-minute audit
- Send a test newsletter to a Gmail address and open Show original. Record SPF, DKIM and DMARC results and their domains.
- Confirm your platform signs with DKIM for your own domain, not only its shared domain.
- Look up your domain's DMARC record. If none exists, start with p=none and reporting (see our DMARC rollout guide).
- Confirm marketing emails carry List-Unsubscribe and List-Unsubscribe-Post headers; Google documents both headers for one-click unsubscribe. [1]
- Confirm unsubscribes take effect within 2 days. [3]
- If you send a few thousand or more Gmail messages a day, register the domain in Postmaster Tools and watch the spam rate.
Who handles what: your platform or you
Platforms differ, so treat this split as a planning guide and confirm each line in your platform's help center. The platform usually runs the sending servers, TLS and reverse DNS. It usually adds unsubscribe links and headers to marketing campaigns and processes the unsubscribes. You usually own the DNS records for your domain: the DKIM keys or CNAMEs the platform gives you, any SPF change, and the DMARC record. You also choose the From address, the list you upload and how often you send.
The split matters when something fails. A missing DKIM signature for your domain is a DNS task on your side. A spam rate that keeps climbing is a list-quality problem, and the platform cannot fix that for you.
Common mistakes
- Using a free Gmail or Yahoo address as the From address on a platform. You cannot publish DMARC or DKIM for a domain you do not own.
- Assuming the platform's green "authenticated" badge means alignment. Check the actual message headers.
- Sending a re-engagement blast to a list nobody has mailed in a year. Clean it first.
- Treating receipts and newsletters as one stream. Google requires one-click unsubscribe only for marketing and promotional messages. [2]
Questions before you decide
Am I a bulk sender if I only email 800 people?
Not under Google's definition, which is close to 5,000 or more messages to personal Gmail accounts in 24 hours, counted across the primary domain. The all-sender requirements still apply, and meeting the bulk requirements is good practice.
Does a mailto unsubscribe link satisfy one-click unsubscribe?
No. Google's FAQ says mailto and URL unsubscribe links do not meet the one-click requirement; it asks for List-Unsubscribe headers per RFC 8058 on marketing and promotional messages.
Do receipts need one-click unsubscribe?
Google's FAQ says one-click unsubscribe is required only for marketing and promotional messages, and gives password resets, reservation confirmations and form submission confirmations as transactional examples.
Sources & verification
Product details and prices can change. Check the linked provider before buying.
- Gmail Help: Email sender guidelines Accessed 13 Oct 2026
- Gmail Help: Email sender guidelines FAQ Accessed 13 Oct 2026
- Yahoo Sender Hub: Sender best practices and requirements Accessed 13 Oct 2026
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