Email Setup

KithFlow sends outbound emails through your own provider so replies land in your domain and deliverability stays under your control. You also need to configure an inbound webhook so the AI Inbox can triage replies.

Outbound: Connect an Email Provider

Go to Settings → Email Provider and choose one of:

Option A — Resend (Recommended)

1. Create a free account at resend.com
2. Add and verify your sending domain in the Resend dashboard
3. Copy your Resend API key (starts with re_)
4. Paste it into KithFlow under Settings → Email Provider → Resend
5. Enter your From address (must be on your verified domain, e.g. outreach@yourdomain.com)

Option B — SMTP

For Zoho, Google Workspace, SendGrid, Postmark, or any other SMTP provider:

1. Go to Settings → Email Provider → SMTP
2. Enter your SMTP host, port, username, and password
3. Set your From address

Common SMTP settings:

Inbound: Reply Routing (AI Inbox)

The AI Inbox works by receiving inbound replies via a webhook. When a prospect replies to your outreach email, Resend forwards it to KithFlow, which classifies it with Claude and routes it to the right lane.

Step 1 — Set up a Reply Subdomain

Create a subdomain for receiving replies, e.g. reply.yourdomain.com. This keeps reply routing separate from your main mail.

Add the following MX record in your DNS provider (Ionos, Cloudflare, etc.):

Type:     MX
Host:     reply
Value:    feedback-smtp.us-east-1.amazonses.com (Resend's MX)
Priority: 10
TTL:      3600

Step 2 — Configure Resend Inbound

1. In your Resend dashboard, go to Domains → [your reply subdomain] → Inbound
2. Set the forwarding URL to: https://api.kithflow.com/api/v1/webhooks/inbound-email
3. Resend will display a Webhook Secret — copy it

Step 3 — Add the Webhook Secret to KithFlow

1. Go to Settings → Integrations → Inbound Webhook
2. Paste the webhook secret from Resend
3. Set your Inbound Reply Address to replies@reply.yourdomain.com
4. Click Save

Step 4 — Update Your Sequence Reply-To

In your email sequences, set the Reply-To header to replies@reply.yourdomain.com. This ensures that when prospects reply, their email goes to your Resend inbound endpoint, not your main inbox.

Step 5 — Test the Setup

Send a test reply to replies@reply.yourdomain.com. Within 30 seconds it should appear in your Inbox page with a classification of neutral.

DNS Notes for Zoho / Custom Mail Providers

If you are using Zoho or another provider for your primary email and Resend only for sending + inbound, you need to configure DNS carefully to avoid SPF conflicts.

Merged SPF Record

Do not create two separate SPF records. Merge them into one:

v=spf1 include:zoho.eu include:amazonses.com ~all

Replace zoho.eu with your provider's SPF include. Check your current SPF record and append the new include rather than replacing it.

DKIM

Add the DKIM records for both Zoho and Resend. Multiple DKIM records with different selectors are supported — they will not conflict.