Delivery
In sending reports, usually a receiving server accepting a message with a 250 reply after the message data; it says nothing about whether the message reached the inbox or the spam folder.
What it means
Three stages are easy to confuse. Accepted means the receiving server answered 250 after the message data and took responsibility for the message (RFC 5321). Delivered, strictly, is the hand-over into the recipient's mailbox, and RFC 5598's test for that sense is whether a DSN can be generated; sending platforms usually report accepted messages as delivered. Placement is where in the mailbox the message landed, the inbox, a tab, spam or quarantine, which SMTP never tells the sender.
So a delivery rate near 100 per cent can hide a spam-folder problem. Placement has to be inferred from other signals: seed tests, provider tools such as Google Postmaster Tools, complaints, and replies.
Related terms
On this site
Sources
What this definition rests on. The wording is ours; the facts are theirs.
- RFC 5321, section 6.1: Reliable Delivery and Replies by Emailrfc-editor.org
- RFC 5598, section 4.3.3: Mail Delivery Agent (MDA)rfc-editor.org
- Google, Gmail Help: Email sender guidelinessupport.google.com
All 432 terms in the glossaryThe wiki: blocklists and bounce codes