Deliverability
Bulk sender requirements
The rules Gmail and Yahoo enforce, since 2024, on anyone sending around 5,000 or more emails a day to their users: full authentication, one-click unsubscribe and a low spam rate.
What the rules require
- SPF and DKIM set up for your sending domain.
- A DMARC record, at least p=none, with the From domain aligned to SPF or DKIM.
- Valid forward and reverse DNS for sending IPs.
- One-click unsubscribe (the List-Unsubscribe and List-Unsubscribe-Post headers) on marketing mail, with requests honored within two days.
- A spam rate below 0.3%, ideally below 0.1%, as reported in Postmaster Tools.
What happens if you don’t comply
Non-compliant mail is increasingly rejected or sent to spam. Once a domain is classed as a bulk sender, it stays that way, so the rules apply even on quieter days.
Good practice for everyone
Even if you send less than 5,000 emails a day, these rules describe what mailbox providers expect from every sender. Treat them as the baseline.
Let MailCraft handle the details
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Start freeRelated terms
Full glossaryAuthentication
DMARC
A DNS policy that tells receiving servers what to do with mail that fails SPF/DKIM alignment (none, quarantine, or reject), and provides aggregate reports on who’s sending as your domain.
Email types & metrics
List-Unsubscribe header
An email header that lets recipients unsubscribe in one click directly from their inbox, without opening the message — required by major providers for bulk senders.
Sending & delivery events
Complaint (FBL / feedback loop)
A signal from a mailbox provider that a recipient marked your email as spam. Feedback loops relay these back to senders so the address can be suppressed.