---
title: "Set daily send limits & auto-adjust per mailbox | FirstSales"
description: "Control how many emails each mailbox sends per day — set a fixed limit, let auto-adjust manage it nightly, or cap it with a send ceiling."
canonical: "https://firstsales.io/tutorial/per-mailbox-sending-limits/"
---

[Home](/)/[Tutorials](/tutorial/)/Set daily send limits & auto-adjust per mailbox

Mailboxes

# Set daily send limits & auto-adjust per mailbox

Control how many emails each mailbox sends per day — set a fixed limit, let auto-adjust manage it nightly, or cap it with a send ceiling.

6 min read·Intermediate·8 steps

1. 1  
## Connectors → open a mailbox → Details tab  
Click a connected email account and stay on the **Details** tab; scroll to **Sending Configuration**.
2. 2  
## Understand Daily Limit  
This is how many emails the mailbox may send per day — a range of **20–500**, default **50**. New or cold mailboxes should start low.  
![Understand Daily Limit](/tutorials/mailbox-limits-01-sending-config.webp)
3. 3  
## Decide: auto-adjust or fixed  
With **Auto-adjust** on (the default), FirstSales manages the daily limit nightly from yesterday's **Sending health**, and the number is read-only. Turn it off to type a fixed limit and click **Save**.
4. 4  
## Set a Send ceiling (optional)  
Enter a **Send ceiling** to cap daily sends — auto-adjust still ramps underneath it but never exceeds it. Leave it blank for no cap. Click **Save**.
5. 5  
## Read the Sending health bar  
The 0–100% **Sending health** score is computed nightly from the prior day's metrics and drives auto-adjust. A low score means the limit gets pulled back automatically.
6. 6  
## Check the last auto-adjust  
When present, the info popover next to **Sending health** shows when the limit was last changed and why (tier and reason).
7. 7  
## Repeat per mailbox  
These settings are per mailbox — set them on every sending account, keeping cold ones conservative and aged ones higher.
8. 8  
## Rotate, don't overload  
To send more total volume, add mailboxes to the campaign's sender pool rather than pushing one mailbox past a safe limit — see the safe-scaling tutorial.

## Pro tips

Hard-won shortcuts that keep warm-up on track.

1

### Leave auto-adjust on and add a ceiling

The safest setup for most users: auto-adjust ramps volume with health, and a Send ceiling stops it climbing past a number you're comfortable with.

2

### Fixed limits are for known-good, aged mailboxes

Turn auto-adjust off only when you have a mailbox with a stable reputation and a volume you already trust.

3

### Watch the health score after warm-up

A dip in the nightly Sending health score is your early warning; auto-adjust will throttle before deliverability tanks — don't override it back up.

4

### More volume = more mailboxes

500/day is the per-mailbox ceiling. Scale by rotating across several senders in the campaign, not by fighting one mailbox's limit.

## Frequently asked questions

Where do I set a mailbox's daily limit?

**Connectors** → open the mailbox → **Details** tab → **Sending Configuration**.

What's the range and default?

**20 to 500** emails per day, default **50**.

What does Auto-adjust do?

It sets the daily limit nightly based on yesterday's **Sending health**; while it's on, the limit field is read-only.

What is the Send ceiling?

An optional hard cap. Auto-adjust ramps underneath it but never goes above it; leave it blank for no cap.

How is Sending health scored?

Nightly, from the previous day's sending metrics; it drives every auto-adjust decision.

Can I set a limit per campaign instead?

No — the limit is per **mailbox**. Campaign-level volume comes from how many mailboxes you assign as senders.

Should I raise the limit right after warm-up?

Let auto-adjust do it. A manual jump risks a spam spike; the nightly ramp is safer.

Why did my daily limit change on its own?

Auto-adjust changed it based on **Sending health**; the info popover shows the exact time and reason.

## Ready to put this into practice?

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