SSalesCrew

What is a unified inbox?

Send from 20 mailboxes and a warm reply can sit in mailbox 14 for a week before anyone opens it.

An admin approves every new account by hand. Nothing is created until then. We reply by email; no newsletter, no sequence.

app.salescrew.io/inbox
The unified reply inbox with classified threads

Unified inbox — A unified inbox is a single view that collects incoming email from many mailboxes, usually every sending account in a cold email setup, so replies can be read and answered in one place. Its purpose is to make sure no reply sits unseen in a mailbox nobody checks.

Also known as: Unibox

Why cold email teams need one

Cold email spreads volume across many mailboxes and domains to protect deliverability. That's good for reputation and bad for reading replies. Nobody logs into twenty accounts every morning, so answers get missed or found days late.

Sending tools solved this with a combined view. Instantly calls its version Unibox. Its help centre (Unibox V2 article, dated March 2026) splits it into two folders. Primary holds "replies from leads that exist in any campaign or list in your workspace", and Others holds replies from people who aren't.

What you do next matters as much. A unified inbox inside a sending tool shows the reply. You still have to create the deal, stop the sequence and tell the owner, often in a second system.

How a unified inbox gathers replies

  1. 1

    Connect each mailbox

    Over IMAP/SMTP or the provider's API.

  2. 2

    Sync new mail

    Each account is checked on a schedule.

  3. 3

    Match replies to leads

    By sender address and thread.

  4. 4

    Label the reply

    Interested, not now, out of office, unsubscribe.

  5. 5

    Answer from the right mailbox

    The reply goes out from the account that sent the first email.

Replying from the wrong mailbox

A unified view makes it easy to answer from whichever account is open. Answer from a different address than the one the prospect wrote to, and they see a new sender. Your history is now split across two accounts. Reply from the mailbox that owns the thread.

One inbox beside the pipeline

SalesCrew's inbox connects Gmail, Outlook and cPanel mailboxes over IMAP/SMTP into one thread list. The first sync of each mailbox brings in its last 90 days of threads.

Questions

What is the difference between a unified inbox and a shared inbox?
A unified inbox combines many mailboxes into one view for you, while a shared inbox is one address, like sales@, that several people work from. Cold email teams use a unified inbox because they send from dozens of accounts. Support teams usually use a shared inbox.
What is Unibox in Instantly?
Unibox is Instantly's name for its unified inbox. Its help centre (March 2026) describes two folders: Primary for replies from leads in your campaigns or lists, and Others for replies from people outside your workspace. You can change a lead's interest status from there.
How many mailboxes can a unified inbox handle?
There is no standard limit; it depends on the tool's plan. What matters more is how often each mailbox syncs. A 5-minute check on 50 accounts feels live, while a daily sync means replies wait up to 24 hours.
Does a unified inbox stop the sequence when someone replies?
Stopping on reply is a sequence setting, not part of the inbox view. Check two cases in your tool: a reply from a colleague at the same company, and an out-of-office. Either one can let the next step go out when it shouldn't.

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