TL;DR
- Both require SPF, DKIM and DMARC, one-click unsubscribe for marketing mail, and a spam rate under 0.3%.
- Neither publishes a bounce-rate limit. Both tell you to keep recipient addresses valid and to cut volume if mail bounces.
- Verification helps with the bounce side only. It won't fix authentication or complaints.
What Google requires
From Google's email sender guidelines (checked 2026-10-18), for senders of 5,000 or more messages a day to Gmail accounts:
- Set up SPF and DKIM, plus DMARC (the policy can be "none"). The From domain must align with the SPF or DKIM domain.
- Valid forward and reverse DNS records, and TLS.
- One-click unsubscribe for marketing and subscribed messages, plus a clearly visible unsubscribe link in the body.
- Keep the Postmaster Tools spam rate below 0.30%. The page also advises staying below 0.10%.
What Yahoo requires
From Yahoo's sender best practices (checked 2026-10-18):
- Implement SPF and DKIM and publish a DMARC policy of at least p=none that passes.
- A working List-Unsubscribe header with one-click support for marketing mail, and honour unsubscribes within 2 days.
- Keep your spam rate below 0.3%.
What they say about bounces
No bounce number. The relevant wording is qualitative:
- Google: automatically unsubscribe recipients who have multiple bounced messages, and if messages start bouncing or being deferred, reduce volume until the error rate drops, then increase slowly. It also says to confirm each address before subscribing and not to buy addresses.
- Yahoo: monitor hard and soft bounces, reduce invalid recipients, and remove invalid recipients promptly.
Sending tools set their own limits instead: for example Instantly pauses above 5% after 200 sends. See how many bounces burn a domain and the benchmarks.
Where verification fits
| Requirement | Does verification help? |
|---|---|
| SPF, DKIM, DMARC | No. Use the authentication checker. |
| One-click unsubscribe | No. |
| Spam rate under 0.3% | Indirectly. A list full of dead or scraped addresses is a sign of poor sourcing, and complaints tend to arrive with bounces. It doesn't fix a bad offer. |
| Keep recipients valid, cut bounces | Yes. Remove undeliverable and disposable addresses before sending; set catch-alls aside. |
Practical rule: verify every list before the first send, re-verify when it ages (schedule), and treat bounces as a stop signal. For fresh domains, use the new domain checklist.
These guidelines change. Check the two pages above for the current text before relying on this summary. Cold email isn't always "bulk" under Google's 5,000-a-day definition, but the practices are sound at any size.