Daily limits and which mailboxes send

Set how much each mailbox sends a day and when, and choose which mailboxes a campaign sends from

Updated 11 October 2026

Every mailbox has a daily cap, a sending window and the days it sends on. A campaign sends from the mailboxes you put in its pool, spreading the emails across them, and can have a cap of its own on top. This guide shows where each limit is and how they work together.

Note: The mailbox's cap wins. A campaign can never make a mailbox send more than its daily cap, and warm-up emails count toward the same cap.

Note: While a mailbox is warming up, its cap for campaigns starts at 5 a day and rises to the full cap over 14 warm-up days, whatever the cap says.

Note: Keep caps modest. 30 to 50 a day per mailbox is what keeps new mailboxes out of spam; two to five mailboxes per domain is the rule the Mailboxes tab checks.

Before you start

A connected mailbox
About 5 minutes

The mailbox's limits

Step 1: See a mailbox's cap and window

In the left menu, point to the paper plane icon to open Outreach, then click Email Accounts.
Each card shows Sent today against the daily cap, the Window it sends in, its Timezone and its Days.

Step 2: Change them

Click Settings on the card.
Set Daily cap to the most emails the mailbox sends in a day, campaigns and warm-up together.
Set Window start and Window end, the hours it sends in, in the mailbox's timezone.
Min gap between sends is the shortest pause between two emails from this mailbox.
Tick Send on weekdays only to keep weekends quiet, then click Save changes.

Which mailboxes a campaign sends from

Step 3: Open the campaign's Mailboxes tab

Open the campaign under Campaigns and click the Mailboxes tab.

Step 4: Pick the pool

Tick each mailbox that should send this campaign, then click Save mailboxes.
Leads are spread across the pool, so three mailboxes with a cap of 40 send up to 120 a day between them.
A paused mailbox stays in the pool but sends nothing until it is resumed.

Step 5: Cap the whole campaign

Open Deliverability below the pool.
Daily send cap for this campaign limits the campaign as a whole, across every mailbox in its pool. Default follows your Sender settings, No cap lets the mailboxes decide, Cap sets a number.

Step 6: Pace the sends

Open Sending rules.
Gap between sends is the least time between two emails from this campaign, and Random extra wait adds a little on top so sends do not land on a clock.
Limit emails per company stops the campaign writing to too many people at one company.

Troubleshooting

The campaign sends far fewer than the cap

Look at the mailbox cards. A mailbox that is warming up sends only a few campaign emails a day at first, and warm-up emails use the same cap. Outside the sending window, and on weekends on a weekdays-only mailbox, nothing goes out.

Sent today says 0 / 40 all day

The mailbox is not in any campaign's pool, or the campaign is paused or outside its schedule. Open the campaign's Mailboxes tab and tick it, then check the campaign's status.

Can I send more than 2,000 a day from one mailbox?

No. 2,000 is the most the cap allows, and sending anywhere near it from one mailbox gets it marked as spam. Add mailboxes to the pool instead.

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