Delivery and placement are two different outcomes
A message SES reports as delivered has been accepted by the recipient's mail server — that's delivery. What that mail server then does with it internally (primary inbox, a promotions or social tab, or the spam folder) is placement, decided by the receiving provider's own filtering logic, and it happens entirely after the point where a sender's own event data stops. A 100% delivery rate says nothing about placement.
There is no reliable way to measure it directly
Unlike delivery, bounce, or complaint, placement isn't reported back to a sender through any standard mechanism — there's no event, no webhook, no API call that tells you a specific message landed in spam versus the primary inbox for a specific recipient. Third-party seed-list panels (sending to a controlled panel of test mailboxes across providers and checking where each copy landed) are the closest proxy the industry has, and even those only sample a handful of provider configurations out of the enormous variety recipients actually use.
Authentication and reputation are the levers, not a setting
There's no placement dial to turn — the closest a sender gets to influencing it is the same set of levers that drive every other deliverability outcome: passing SPF/DKIM/DMARC, keeping bounce and complaint rates low, sending content recipients actually engage with, and building sending history and reputation over time. Placement is the downstream result of all of that, not a separate thing to optimize on its own.
No vendor, including AWS, can promise a result
Every major sending platform, and AWS's own documentation, is explicit that inbox placement cannot be guaranteed — it's determined by the receiving provider's proprietary filtering, which is neither disclosed nor stable, and legitimately varies by recipient, by provider, and over time for the exact same sender and content.
Why it matters
Confusing a clean delivery rate with good inbox placement is one of the most common ways a sender misreads their own deliverability health — a domain can show near-perfect delivered/bounced/complained numbers while a meaningful share of that "delivered" mail is actually landing in spam, invisible to every metric the sender can see directly.
Common questions
If SES reports a message as delivered, did it reach the inbox?
It reached the recipient's mail server, which is delivery. Whether that server then routed it to the primary inbox, a secondary tab, or spam is placement — a separate outcome that delivery data doesn't tell you anything about.
How do I measure my actual inbox placement rate?
There's no direct, standard way — no event or API reports it. Third-party seed-list panels that send to controlled test mailboxes across providers are the closest proxy available, though they only sample a fraction of real-world provider configurations.
Can Wraps or AWS guarantee my mail lands in the inbox?
No, and neither can any other sending platform. Placement is decided by the receiving mailbox provider's own filtering logic, which is undisclosed and can vary by recipient and over time even for identical senders and content.