Bulk sender
Someone sending large volumes (providers often use ~5,000 messages/day to their users as a threshold).
Say it out loud
“Above five thousand a day to one provider, stricter rules apply. Most of us cross that line without noticing.”
Gmail, Yahoo and Microsoft publish extra requirements for high-volume senders to their consumer inboxes. The threshold is counted per day, to that one provider's users — not against your total list, and not per month. Below it you still need basic authentication; above it the requirements get specific and enforced.
- 5,000/day
- Gmail personal accounts
- Google, Email sender guidelines
- 5,000/day
- Outlook consumer accounts
- Microsoft, Outlook.com sender requirements
- 94,000 to Gmail, one Tuesday
- 5k — Gmail's bulk threshold
Drawn to scale, which is the point: the threshold is so far left that most senders cross it without ever deciding to. The threshold is Google's; the volume is an example.
Gmail is typically half a consumer list. Count it separately, because the provider does.
You crossed it at nineteen times over, on one ordinary send.
A 12,000-person list still crosses it in one send.
So does a 6,000-person list where most addresses are Gmail.
Per day, per provider. Not your list size, not your monthly total. This is the single most misread number in email.
Nobody's
Nothing to action — it changes a number or a risk you report.
What people get told
The claim. “We only have a few thousand subscribers, so bulk rules do not apply.”
Actually. The count is messages to one provider in one day. A single campaign to six thousand people, half of them on Gmail, is three thousand Gmail messages — under the line that day, over it the moment you send twice. Authentication is required of everyone regardless.
The dated rules behind this
A definition is not a citation. These are the pages with the primary source, the date it was published, and what to do about it.
- Gmail enforces authentication, PTR, TLS and a 0.30 percent spam rateGlobal · Gmail
- Yahoo requires authentication and a spam rate below 0.3 percentGlobal · Yahoo
- Outlook rejects unauthenticated mail from high-volume sendersGlobal · Microsoft
- iCloud Mail rejects bulk mail that misses Apple's sender requirementsGlobal · Apple
See also
Where this sits
Stop 4, identity gets checked. The receiver works out whether the message really comes from who it says it does.