Connect InboxKit to Instantly, SmartLead, and 14 More Sequencers

By Saksham JainPublished on: Mar 31, 2026 · 7 min read · Last reviewed: Mar 2026

InboxKit connected sequencers — InboxKit Sequencers page showing 7 connected accounts across Instantly, ReachInbox, SendKit, and SmartLead.

InboxKit mailbox exports — 3,093 successful mailbox exports to sequencer platforms. Status tracking and retry functionality built in.

TL;DR

InboxKit works with 24+ sequencer platforms. Here is how to connect your mailboxes to each one, with exact steps, connection methods, and troubleshooting tips.

Supported Sequencer Platforms

InboxKit integrates with 24+ cold email and outreach platforms. Here is the full list with connection methods:

Sequencer	Connection Method	Setup Time	Auto-Export?	Source
Instantly	API key + CNAME	3 min	Yes (with SendKit)	instantly.ai/integrations
SmartLead	API key + CNAME	3 min	No	smartlead.ai/integrations
SendKit	API key	2 min	Yes (native)	sendkit.ai
Lemlist	SMTP/IMAP credentials	5 min	No	lemlist.com
Apollo	SMTP/IMAP credentials	5 min	No	apollo.io
Woodpecker	SMTP/IMAP credentials	5 min	No	woodpecker.co
ReachInbox	API key + CNAME	3 min	No	reachinbox.ai
Reply.io	SMTP/IMAP credentials	5 min	No	reply.io
Saleshandy	SMTP/IMAP credentials	5 min	No	saleshandy.com
HubSpot	SMTP/IMAP credentials	5 min	No	hubspot.com
Outreach	SMTP/IMAP credentials	5 min	No	outreach.io
Close	SMTP/IMAP credentials	5 min	No	close.com
Mailshake	SMTP/IMAP credentials	5 min	No	mailshake.com
QuickMail	SMTP/IMAP credentials	5 min	No	quickmail.io
Klenty	SMTP/IMAP credentials	5 min	No	klenty.com
EmailBison	API key	3 min	No	emailbison.com

API key + CNAME: Faster, supports one-click export. Used by Instantly, SmartLead, SendKit, ReachInbox.
SMTP/IMAP credentials: Universal method that works with any platform. Requires entering server settings manually.

Source: InboxKit documentation (docs.inboxkit.com) and each sequencer's integration documentation.

Connecting to Instantly (Most Popular)

Instantly is the most popular sequencer among InboxKit users. Here is the exact process:

Step	Action	Time
1	Go to InboxKit Sequencers page	10 sec
2	Click 'Add Sequencer' and select Instantly	10 sec
3	Enter your Instantly API key (from Instantly Settings > Integrations)	30 sec
4	Configure CNAME record (InboxKit provides the value)	1 min
5	Select mailboxes to export	30 sec
6	Click Export. mailboxes appear in Instantly within minutes	30 sec

Total time: ~3 minutes.

CNAME configuration: Instantly requires a CNAME record to verify domain ownership. InboxKit provides the exact CNAME value in the sequencer setup flow. The record typically propagates within 15-30 minutes.

Auto-export with SendKit: If you use SendKit as your sequencer, InboxKit supports automatic export. new mailboxes are pushed to your SendKit account without manual intervention (see screenshot showing 'Auto Export' badge).

Source: InboxKit Sequencers page (see screenshot), Instantly integration documentation.

Connecting via SMTP/IMAP (Universal Method)

For sequencers that don't support API integration, use SMTP/IMAP credentials. This works with ANY email platform.

Google Workspace SMTP/IMAP settings:

Setting	Value	Source
SMTP Server	smtp.gmail.com	support.google.com/a/answer/176600
SMTP Port	587 (TLS) or 465 (SSL)	Google Workspace Admin Help
IMAP Server	imap.gmail.com	support.google.com/a/answer/9003945
IMAP Port	993 (SSL)	Google Workspace Admin Help
Username	Full email address	-
Password	App-specific password	support.google.com/accounts/answer/185833

Microsoft 365 SMTP/IMAP settings:

Setting	Value	Source
SMTP Server	smtp.office365.com	learn.microsoft.com
SMTP Port	587 (TLS)	Microsoft documentation
IMAP Server	outlook.office365.com	learn.microsoft.com
IMAP Port	993 (SSL)	Microsoft documentation
Username	Full email address	-
Password	Account password or app password	-

Important: Google Workspace requires app-specific passwords (not your regular password) for SMTP/IMAP connections. Generate one at myaccount.google.com/apppasswords.

Source: Google Workspace SMTP settings (support.google.com/a/answer/176600), Microsoft 365 SMTP settings (learn.microsoft.com).

Bulk Export and Management

At scale, you need to export hundreds of mailboxes efficiently.

InboxKit export capabilities:

Feature	Details	Source
Bulk export	Export all mailboxes to a sequencer in one click	InboxKit Exports page
CSV export	Download mailbox credentials as CSV	InboxKit Mailboxes page
Export history	Track all 3,093+ exports with status	InboxKit Exports page (see screenshot)
Failed export retry	One-click retry for failed exports	InboxKit Exports page
Auto-export (SendKit)	Automatic push on new mailbox creation	SendKit integration

Mailbox email address
Target sequencer
Status (Completed/Failed/Pending)
Timestamp
Retry option for failures

At 858 mailboxes and 3,093 exports, InboxKit handles large-scale export operations reliably. The average export completes within 2-5 minutes.

Source: InboxKit Exports page data (see screenshot).

Troubleshooting Common Integration Issues

The most common problems and their fixes:

Issue	Cause	Fix	Frequency
CNAME not verifying	DNS propagation delay	Wait 30 min, check with DNS Checker	30% of issues
SMTP authentication failed	Wrong password type	Use app-specific password (Google)	25% of issues
IMAP connection timeout	Port blocked	Use port 993 with SSL, check firewall	15% of issues
Export stuck at 'Pending'	Sequencer API rate limit	Wait 5 min, retry	15% of issues
Mailboxes not appearing	Sequencer cache	Refresh sequencer mailbox list	10% of issues
Duplicate mailbox error	Already exported	Check sequencer for existing account	5% of issues

'Less secure app access' is no longer available. You MUST use app passwords or OAuth.
App passwords require 2-Step Verification to be enabled first.
Source: Google security documentation (support.google.com/accounts/answer/185833)

Modern Authentication (OAuth) may be required by organization policy.
Legacy SMTP authentication must be enabled per-mailbox in Exchange Admin Center.
Source: Microsoft 365 SMTP auth documentation (learn.microsoft.com)

Frequently Asked Questions

Instantly and SendKit have the deepest integration (API key + auto-export). SmartLead and ReachInbox also support API connections. All 24+ platforms work via SMTP/IMAP.

Technically yes, but we do not recommend it. Each mailbox should be connected to one sequencer to prevent sending conflicts and maintain deliverability.

API exports (Instantly, SmartLead): 2-5 minutes. SMTP/IMAP manual setup: 5 minutes per mailbox. Bulk CSV export: instant download.

Yes. Google uses smtp.gmail.com with app passwords. Microsoft uses smtp.office365.com with account passwords. InboxKit's export feature handles this automatically.

Check the Exports page for error details. Most failures are CNAME propagation delays or API rate limits. Use the one-click retry button after fixing the issue.