In this article
Unknown sender, held email
Every incoming email gets one question first: is this sender a known person at a real company?
Mach checks the CRM, where your team keeps its customer records, synced before any mail is read. A clear match files the email to that person's conversation.
No match means the email is held, whole, and nothing automatic acts on it. Mach keeps it, counts it and tries again as the records grow.
One firm's mail, counted
Here is the full count for one firm we work with, exported 20 October 2026.
| Outcome | Messages | Share |
|---|---|---|
| Seen | 49,079 | 100% |
| Filed to the right conversation | 38,510 | 78% |
| Held until the sender is known | 10,569 | 22% |
| Dropped | 0 | 0% |
Held is 22% of all mail seen, which means the records are still young. The share falls as people are added and each sync checks again. Known misfiles so far: zero of the 38,510 filed.
Each held email keeps three times: when it came, when it was held and when it was last checked. If arrivals rise while matches stall, the records are behind. That is a to-do list, not an error.
What one wrong filing would cost
Here is the failure the hold rule prevents. An agency replies for its client, from the agency's own address.
A tool that matches by display name or domain files that reply under the client. The thread now shows words the client never wrote.
Follow-ups quote the wrong person. An opt-out, if one comes, lands on the wrong record. Mail is the record of what was promised to whom.
A filed reply changes what Mach may do
Filing is not just record keeping. When a reply is filed to a person, that person's automatic steps stop at once.
That only works when the filing is right. A reply filed to the wrong person stops the wrong steps. The real person keeps getting emails.
So the hold rule is also a sending rule. The checks from lead to meeting depend on mail filed correctly.
Four questions for any inbox tool
Ask what happens to an email from an unknown sender. The only safe answers are hold it or ask.
Ask for the count above: seen, filed, held and dropped, from the tool's own counters. We learned to distrust untested counters in our own build.
Ask what checks the held pile again, and when. Ask for the dropped count, and expect zero.
Judge an inbox tool by how little it misfiles, not by how little it holds.
Common questions
What happens when a held sender becomes known weeks later?
The next sync files their held emails to the new person, with the original times. The conversation reads in order.
Where the numbers come from
Counts from the mail records of one firm we work closely with, exported 20 October 2026.
