Overview & Key Benefits
The Microsoft Outlook integration provides two key capabilities to help improve your program participation rates:
Send from Outlook (Read & Send): Send program emails directly from your team members' Outlook/Microsoft 365 accounts instead of from Clozd's domain. By sending emails directly from your mailbox, you leverage your organization's existing email relationship with your contacts rather than Clozd's shared infrastructure. This significantly reduces the likelihood that program emails will be blocked by spam filters or corporate firewalls, leading to higher delivery rates and better participation. When using Send capabilities, you also have access to all Inbox Monitoring capabilities (see below).
Inbox Monitoring (Read Only): Monitor connected Outlook inboxes for participant responses when using Outlook integration to send email or when using DKIM to send emails from Clozd using your address as the reply-to address (for more information, see DKIM). By monitoring your inbox for participant responses, Clozd can automatically stop sending follow-up emails to participants who have already replied. This prevents over-communication, improves the participant experience, and ensures your team doesn't send unnecessary reminders to engaged participants.
This article will be broken out into the following sections:
Setup process
Step 1: Connect Outlook accounts
Organization administrators can invite team members to connect their Outlook/Microsoft 365 accounts. You can choose between two permission levels:
Read & Send: Allows Clozd to send emails directly from Outlook AND monitor the inbox for responses.
Read Only: Allows Clozd to monitor the inbox for participant responses (useful when combined with DKIM).
Organization Admin instructions:
- From your organization’s home page, navigate to Admin → Integrations → Outlook (click Settings on the Outlook banner).
- Click + Add to choose the mailbox you want to connect.
- Choose the correct permissions (Read & Send or Read Only) and click Invite.
- The mailbox owner will receive a verification email. Once authentication is complete, you’ll see the account listed as Active with the selected permission level.
- Edit, Resend Verification, or Delete an integration using the actions menu.
Note: Some organizations require a Microsoft 365 admin to approve third-party apps before users can authenticate. If authentication fails due to admin approval requirements, contact your Microsoft 365 admin to approve the Clozd app, then try again.
User instructions:
- Open the verification email you received from Clozd.
- Click the Authenticate with Microsoft button.
- Sign into the correct Microsoft account for the mailbox you’re connecting and accept the requested permissions.
Step 2: Configure email settings in your sequence
Once Outlook accounts are connected, you can configure your sequences to send from those accounts.
- From your program’s home page, navigate to Configuration → Feedback Collection → Sequences.
- Create a new sequence or edit an existing one.
- In the Email Settings section, select Email Integration.
- Choose the connected Outlook mailbox from the dropdown list.
- In each email in the sequence, you can choose From {{Org Name}}. Selecting this option will show the Outlook mailbox as both the sending and receiving address.
Note: If you also have DKIM configured, you’ll see both options in Email Settings. Make sure to select the Outlook/Microsoft 365 account with the Email Integration label if you want to use the Outlook Integration feature.
Step 3: Create and send distributions
Once your sequence is configured, you can create distributions as usual:
- Create a manual distribution or use an automated workflow.
- Select the sequence configured with Outlook integration.
- The system will validate that your distribution doesn't exceed daily sending limits (see below).
- Emails will be sent directly from the connected Outlook mailbox.
Expected functionality
Inbox monitoring (Read Only)
When you connect an Outlook mailbox with Read Only permissions, Clozd monitors the inbox for participant responses.
- Clozd uses Microsoft Graph subscriptions (webhooks) to receive notifications for replies and certain delivery events when available.
- When a participant responds to a program email, Clozd automatically identifies the response.
- The sequence for that participant is immediately discontinued. No further follow-up emails will be sent to participants who have replied.
- This works with DKIM-configured emails or emails sent from an integrated Outlook mailbox.
Email sending (Read & Send)
- Emails are sent directly from the connected Outlook/Microsoft 365 mailbox.
- Recipients will see the email as coming from your team member's email address.
- Emails will appear in the Sent folder of the connected mailbox.
- When using Read & Send permissions, inbox monitoring is also active (see above).
Daily sending limits
To protect your mailbox from being flagged as a bulk sender, Clozd enforces a limit of 2,500 emails per day per connected Outlook mailbox.
- Manual distributions: If you try to create a distribution that would exceed the limit, you’ll see a warning message asking you to reduce the recipient list.
- Scheduled distributions: These are validated when the scheduled send time arrives. If the distribution would exceed the limit, it will fail and you’ll receive a notification.
- Automated distributions: These are checked each time the workflow attempts to create a distribution. If it would exceed limits, the distribution will fail and participants will remain in Ready for Distribution status until the next attempt.
Status and tracking
- You can view email delivery status in Distribution History.
- Email statuses include: Sent, Bounced, Failed, Responded, Scheduled, Opted Out, and Marked Spam.
- Workflow participant statuses update appropriately based on email delivery.
Note: Email “open” tracking is not currently supported for Outlook integration.
Managing connected accounts
In the Outlook integration settings page, you can:
- See which mailboxes are connected and their permission levels (Read Only vs Read & Send)
- Resend verification emails if someone needs to reconnect
- Edit permissions (upgrading to Read & Send requires re-authentication)
- Remove connected mailboxes
Note: You cannot delete an Outlook integration that is currently being used in an active sequence. You must first remove it from all sequences before deletion.
Frequently asked questions
What's the difference between Outlook integration and DKIM?
DKIM (DomainKeys Identified Mail) allows Clozd to send emails that appear to come from your domain, but they still use Clozd's email infrastructure. Outlook integration with Read & Send permissions sends emails directly from your Outlook/Microsoft 365 mailbox, which often provides better deliverability.
You can use both features together:
- DKIM + Outlook Read Only: Send emails from your domain via DKIM while monitoring your inbox for responses.
- Outlook Read & Send alone: Send directly from Outlook with automatic inbox monitoring included.
Why is there a daily sending limit?
Microsoft 365 enforces service limits and can throttle or restrict sending patterns. Clozd applies product guardrails to reduce risk and keep sending healthy.
What happens if I exceed the daily limit?
If a distribution would cause you to exceed the daily limit:
- Manual distributions: You’ll see an immediate warning and need to reduce your recipient list.
- Scheduled or automated distributions: The distribution will fail, you’ll receive a notification, and participants will remain in their current workflow status until the next attempt.
Is the Outlook integration secure?
Yes. The Outlook integration uses secure OAuth consent via Microsoft Graph with least-privilege scopes.
- Clozd never sees nor stores your Microsoft password.
- Clozd does not scan entire mailboxes or store message bodies beyond what’s needed to determine response or delivery status.
- Permissions can be revoked by your Microsoft 365 admin or the mailbox owner.
What happens if the Outlook connection breaks?
If the authentication token expires or the connection is lost:
- The integration status will change to Inactive.
- You may receive a notification requesting re-authentication.
- Any distributions using that mailbox for sending may be discontinued, and new distributions may fail until re-authenticated.
Can I send from multiple Outlook mailboxes?
Yes! You can connect multiple Outlook accounts from different team members. This allows you to:
- Distribute email sending across multiple accounts to handle larger volumes
- Have different programs send from different team members
- Ensure continuity if one account becomes unavailable
However, only one Outlook account can be used per sequence.
Will emails appear threaded in my Outlook account?
It depends how the sequence is configured in your distribution. If you have enabled threading, then it’s possible to have emails in the sequence show up in the same thread.
For example, if you want to send the first email from one of your team member’s Outlook account, and then have subsequent emails come from Clozd in the same thread, that’s possible.
What happens to automated workflows if I delete a connected Outlook account?
You cannot delete an Outlook integration that is actively being used in a sequence. You must first:
- Remove the Outlook integration from all sequences that use it
- Update any workflows that use those sequences
- Then you can delete the Gmail integration
Who can see and manage Outlook integrations?
Organization administrators can:
- Send invitations to connect Outlook accounts
- See all connected accounts and their status
- Remove integrations
- Manage permissions
Program managers with access to the integrations page can also manage connected accounts.
Need Help?
If you have questions about setting up or using the Outlook integration, please contact your Clozd program manager or reach out to support@clozd.com.