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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.

  1. Connectors → open a mailbox → Details tab

    Click a connected email account and stay on the Details tab; scroll to Sending Configuration.

  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
  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. 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. 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. 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. Repeat per mailbox

    These settings are per mailbox: set them on every sending account, keeping cold ones conservative and aged ones higher.

  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

  • 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.

  • 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.

  • 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.

  • 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.

Mailboxes

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Install with AI

Your coding agent sets up the FirstSales CLI and skills for you.

Prompt for Claude Code

I'm setting up FirstSales (https://firstsales.io), an AI outbound sales platform: campaigns, contacts, a reply inbox, deliverability and lead signals. Help me get my workspace sending real, good emails end to end, from Claude Code.

Read these first so you know how FirstSales works:
- Developer docs and API: https://developer.firstsales.io
- CLI: https://www.npmjs.com/package/@firstsales.io/cli
- Skills for coding agents: https://github.com/firstsalesio/firstsales-skills (read README.md and GUIDE.md)

Setup
1. Install the CLI: npm install -g @firstsales.io/cli
2. Install the FirstSales skills:
   claude plugin marketplace add firstsalesio/firstsales-skills
   claude plugin install firstsales@firstsales
3. Ask me if I already have a FirstSales account. If not, send me to https://app.firstsales.io to sign up.
4. Ask me to create an API key under Settings → API → API Keys, with only the scopes we need.
   Never ask me to paste the key into this chat. Tell me to run this in my own terminal, so the key stays hidden:
   read -rs FS_KEY && firstsales auth login --api-key "$FS_KEY"; unset FS_KEY
5. Run `firstsales whoami` and tell me which workspace and organisation we are connected to.

Then ask me about my business: what I sell, who I sell to (roles, company size, countries), my best customers, and what I use today for outbound (tools, lists, mailboxes). Walk me through:
1. Teaching FirstSales my business: website, offer, proof points and case studies in the knowledge base, so the AI writes like someone who knows the product.
2. Connecting my sending mailboxes and checking my sending domain: SPF, DKIM, DMARC and warm-up. If anything is unhealthy, tell me the exact DNS record to add.
3. Bringing in contacts: import my CSV or CRM export into a clean list, remove duplicates and bad emails, and block domains I must never email (customers, competitors, my own).
4. Building my first campaign: the right list, senders, steps and timing. Write the sequence with me, show me the drafts, and do not launch until I say yes.
5. Setting up Signals if it fits: find people engaging with LinkedIn posts about topics my buyers care about, and turn them into leads.
6. Inviting my team and giving each person the right access.

Once campaigns run, show me how to work the reply inbox from here: which replies need an answer, draft responses in my voice, and move good conversations into deals. If I use Cal.com, connect it so follow-ups can offer my booking link (not the first email).

Throughout, as you learn about my business, proactively suggest and help create:
- Reply templates for the questions and objections my prospects are likely to raise, based on my product, site and codebase if you can see them.
- Campaign ideas and segments worth testing, with the reason for each.

Safety rules:
- Show every change as a dry run (--dry-run) first and wait for my yes. Never send emails, launch campaigns or delete anything without my yes.
- Tell me before anything that spends credits, and how many.

Be opinionated. If the docs give a sensible default, just use it. Don't make me choose between five options.