> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tenantcore.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Connecting to Reachkit

> How to add TenantCore-provisioned mailboxes to Reachkit using mailbox credentials.

## Overview

TenantCore does not connect to Reachkit directly. The integration happens at the mailbox level. You retrieve credentials from TenantCore and add them to Reachkit as email accounts. Reachkit supports connecting Outlook and Microsoft 365 accounts via OAuth, which is the recommended method for TenantCore-provisioned mailboxes.

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## Prerequisites

* At least one mailbox provisioned in TenantCore with a **Verified** domain status
* A Reachkit account at [reachkit.ai](https://reachkit.ai)

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## Step 1 — Retrieve mailbox credentials from TenantCore

1. Open the TenantCore app and navigate to the **Mailboxes** page
2. Find the mailbox you want to connect
3. Copy the credentials

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## Step 2 — Add the email account in Reachkit

1. In Reachkit, go to **Inboxes**
2. Click **Connect Inbox** and select **Outlook** or **Microsoft 365**
3. Sign in with your mailbox credentials and click **Accept** when prompted for permissions. This uses secure OAuth.
4. Once the status shows **Connected**, your mailbox is ready for warmup or campaigns.

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## Step 3 — Configure send limits in Reachkit

<Warning>
  Set your Reachkit per-account send limit **at or below** the limit enforced in TenantCore. If Reachkit attempts to exceed the TenantCore limit, Exchange will block the excess messages and Reachkit may log delivery errors.
</Warning>

In Reachkit, open the inbox settings and configure:

* **Daily sending limit** — match this to the TenantCore mailbox limit or set it lower
* **Sending window** — spread sends across business hours rather than sending in bursts

The TenantCore limit is the hard ceiling. Reachkit's limit controls scheduling. Keeping them aligned avoids NDRs and delivery errors in Reachkit's logs.

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## Repeat for each mailbox

Add each TenantCore mailbox as a separate inbox in Reachkit. Reachkit supports unlimited email accounts at no extra cost, so there is no constraint on how many mailboxes you connect.

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## Troubleshooting

**Connection fails**

* Confirm the mailbox password was copied correctly, passwords are case-sensitive
* Confirm the domain shows as **Verified** in TenantCore before attempting to connect
* Confirm the mailbox status is **Active** in TenantCore

**Delivery errors after connecting**

* If messages are being blocked, the Reachkit send limit likely exceeds the TenantCore mailbox limit
* Reduce Reachkit's daily limit to match or fall below the TenantCore limit
* Check TenantCore's enforcement log for blocked events