What the delivery numbers mean

Every sent issue has a report, and the top of it is about delivery rather than engagement: how many addresses the send took on, how many the provider accepted, and what it said about the ones it refused. Open the issue from your issues list and press Report.

The funnel, and what each share is measured against

The funnel runs Sent, Delivered, Opened, Clicked, and each percentage is of the stage above it rather than of the top of the list.

So the open figure is a share of delivered, not a share of sent. That is deliberate: measuring everything against sent hides a delivery problem inside an engagement figure, and “62 per cent of the people it reached opened it” is the sentence worth having. Underneath the funnel sit three more figures for the same issue: unsubscribed, with its own share of delivered, bounced, and complained. The rest of the issue report covers the engagement half, including the per-link table and what each link earned.

What Sent counts

Sent counts the addresses this send actually took on, which is not the same as your subscriber count on the day.

An address already on the suppression list when you pressed send never gets a place in the issue at all, and an address suppressed while the send was still running is skipped rather than mailed. Neither one is counted as a recipient, so the figure does not depend on the minute a complaint happened to arrive. Bounces and complaints covers what puts an address in that position.

What Delivered means, and what it does not

Delivered counts every address handed to your sending provider that has not since bounced or been refused.

Three things follow from that, and they are all worth knowing before you quote the number to a sponsor. A complaint counts as delivered, because the issue arrived and then the reader pressed the spam button. A permanent bounce moves out of the delivered figure as the bounce arrives, so the number falls in the hours after a send rather than holding still. And delivered is not the same as landing in the inbox: a message can be delivered and filed straight into spam, nothing in email reports that, and no platform that tells you otherwise is measuring it. Issues going to spam is the page for that problem.

Why the numbers keep moving after a send

Every delivery, bounce and complaint event recomputes the counts from the send record rather than adding one to a running total.

That is what makes the report safe to read at any moment: a duplicate event cannot inflate anything, and an address that bounces and later attracts a complaint is counted once, as the more serious of the two. It also means the first batch’s deliveries are already arriving while the last batch of a long send is still going out, so a report opened mid-send is describing a moving target.

On your own SMTP server, delivered means less

An SMTP server tells Issue Mint that it accepted the message, and then nothing at all.

There are no delivery, bounce or complaint events over SMTP, so every accepted address stays counted as delivered for ever and the bounced and complained figures stay at zero. That is the honest ceiling of what your own SMTP server can report, rather than a gap in the report, and it is the main practical difference between the sending routes in choosing how you send.

Why some addresses did not arrive

A send with refusals in it carries a section naming how many did not arrive, grouped by the reason the provider gave, commonest first.

A refusal here is not a bounce. It means the message was never accepted, so no mailbox was ever involved, and the provider’s own wording is the useful part of it. “Email address is not verified” means an Amazon SES account still in the sandbox, and no amount of general advice about list quality gets anybody to that answer. Addresses grouped this way are counted separately from the bounced figure, which fills up later and comes from mailboxes rather than from your provider.

The warning on a send that mostly worked

An issue carries a warning when more than 5 per cent of its addresses failed, and the warning names the commonest reason the provider gave rather than leaving you to go looking.

Two other sentences can appear there, both with no threshold at all, because one subscriber who never got the issue is worth a sentence. Addresses nobody ever attempted mean part of the send stopped before it finished, which can be up to 200 addresses for each batch that gave up. Addresses that could not be confirmed as sent mean the send was interrupted partway through a message, so those may or may not have gone out. Both sentences say that we can see the same thing from our side, because both are ours to look into rather than yours.