Connect Smartlead to your Inboxlee mailboxes in under a minute
API key method, CSV fallback, sending limits. Complete guide with every step spelled out.
Rejwan Nirob·Apr 22, 2026·3 min readOnce your mailboxes are provisioned and warming, you can sync them directly to Smartlead in one click. This guide covers the API key method (recommended) and the CSV export fallback.
Step 1 - Generate an API key
In your Inboxlee workspace go to Settings → API keys and click Create new key. Name it "Smartlead sync" and grant mailboxes:read scope. Copy the key.
Step 2 - Connect in Integrations
In Inboxlee dashboard go to Integrations → Smartlead and click Connect. Paste your API key and click Save. Inboxlee will immediately sync all live mailboxes to Smartlead.
Step 3 - Configure sending limits
In Smartlead, open each synced mailbox and confirm the daily sending limit matches your warmup stage. Day 1 through 14 ramp from 5 to 20 emails per day. After day 14, cap at 10 to 20 per day per mailbox for cold outbound. We deliberately stay below the platform ceiling to protect deliverability.
If API sync ever stalls, download the CSV export from Inboxlee → Mailboxes and upload it in Smartlead → Email Accounts → Bulk Import. Same format, same result.
Frequently asked
How do I connect Smartlead to my Inboxlee mailboxes?
Generate an Inboxlee API key (Settings → API keys, mailboxes:read scope), then paste it in Inboxlee → Integrations → Smartlead → Connect. All live mailboxes sync to Smartlead within seconds. CSV bulk-import is available as a fallback if API sync stalls.
What daily-send cap should I use in Smartlead?
10 to 20 emails per mailbox per day for safe cold outbound, after the 14-day warmup. Smartlead will let you set higher and Workspace will technically tolerate up to ~500/day at full reputation, but sustained sends above 20/day correlate with placement decline in our partner-program telemetry.
Does Smartlead read warmup data from Inboxlee or the other way?
Smartlead runs warmup through its own warmup network - inbox-to-inbox synthetic engagement during the 14-day ramp. Inboxlee reads warmup-day, daily volume, and engagement curve back from the Smartlead API so you see everything in one dashboard alongside infrastructure health.
Can I connect Inboxlee to Smartlead without the API key?
Yes - use the CSV export. Inboxlee → Mailboxes → Export CSV downloads every live mailbox in Smartlead's standard import format. Smartlead → Email Accounts → Bulk Import accepts the file directly. Same result, no API plumbing.