Connecting Apollo email to Inboxlee mailboxes
Apollo via SMTP credentials and via the native partner connector. The path that lets you keep one source of truth.
Rejwan Nirob·Jan 15, 2026·4 min readApollo handles cold email natively, with sequences and reply detection. Connecting Inboxlee mailboxes to Apollo gives you the full Apollo workflow with Inboxlee infrastructure underneath.
Two connection paths
Apollo supports two ways to add a mailbox - direct OAuth with Google Workspace (or M365), and SMTP credentials. Both work for Inboxlee mailboxes. OAuth is simpler. SMTP is more flexible.
OAuth path
In Apollo → Settings → Email Accounts → Connect Account → Google Workspace. Sign in with the Inboxlee mailbox credentials (delivered via the secure one-time link). Apollo handles the OAuth handshake. Mailbox connected.
SMTP path
Apollo → Settings → Email Accounts → Connect Account → SMTP. Use the Inboxlee CSV export to get IMAP and SMTP credentials. Paste host, port, username, password into Apollo. Save.
After connecting
- Set the daily send limit to 10 to 20 per mailbox for cold outbound - well below the platform ceiling
- Enable warmup mode if running cold sequences from a fresh mailbox
- Verify reply detection is on - Apollo handles this automatically with Workspace mailboxes
- Group mailboxes by domain for cohort-based sending
Apollo supports CSV bulk import of email accounts. Inboxlee CSV format is compatible. For 10+ mailboxes, this is faster than connecting one at a time.
Frequently asked
How do I connect Apollo email to my Inboxlee mailboxes?
Two paths: OAuth with Google Workspace (simpler - sign in with the Inboxlee mailbox credentials at Apollo → Settings → Email Accounts → Connect → Google Workspace) or SMTP with the credentials from the Inboxlee CSV export. OAuth is recommended for single mailboxes; CSV bulk-import is faster for 10+.
What daily-send cap should I set in Apollo for cold email?
10 to 20 emails per mailbox per day after the 14-day warmup. Apollo will let you set higher and Workspace will technically tolerate close to 500/day at full reputation, but sustained sends above 20/day correlate with placement decline. The platform ceiling is not the safe ceiling.
Does Apollo run mailbox warmup for cold-email mailboxes?
Yes - Apollo has built-in warmup mode that handles the 14-day ramp on connected mailboxes. Enable it for any fresh mailbox before running cold sequences. Inboxlee reads warmup progress back from Apollo where available so you see the curve in one dashboard.
Should I use OAuth or SMTP to connect Apollo to Inboxlee?
OAuth for single-mailbox setups (less to configure, no password to manage). SMTP for bulk - paste credentials from the Inboxlee CSV export once and connect all mailboxes in one upload. SMTP is also the right call if you ever rotate Workspace passwords manually, since OAuth tokens occasionally need re-authenticating.