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      How can I fix issues with messages not sending when Outlook is connected?

      What Should I Do if My Messages Fail to Send with Outlook Connected? Why aren’t my messages sending through Outlook, and how can I resolve it?

      If you're using an Outlook email account with your Investor Matching account and messages fail to send, the issue is most likely due to your SMTP settings being disabled. You may see this error message:

      Invalid login: 535 5.7.139 Authentication unsuccessful, SmtpClientAuthentication is disabled for the Tenant.

      How to Fix It

       

      1. Enable SMTP AUTH in Outlook

      This error occurs because SMTP AUTH is disabled by default for some Outlook and Microsoft 365 tenants.
      You (or your Microsoft admin) will need to enable it.

      Follow Microsoft’s instructions here:
      👉 Enable SMTP AUTH in Outlook (Microsoft Help Article)

       

      2. Enable SMTP AUTH for a Specific Mailbox

      You can enable or disable SMTP AUTH in either the Microsoft 365 Admin Center or Exchange Online PowerShell.

      Using the Microsoft 365 Admin Center:

      1. Open the Microsoft 365 Admin Center.

      2. Go to Users > Active Users.

      3. Select the user, then in the right panel, choose Mail.

      4. Under Email apps, select Manage email apps.

      5. Check the Authenticated SMTP setting:

        • Unchecked = Disabled

        • Checked = Enabled

      6. Select Save changes when finished.

       

      3. Reauthorize Outlook Access in Investor Matching

      After enabling SMTP AUTH, go back to your Investor Matching dashboard to reconnect your Outlook account.

      1. Navigate to Email & Settings > Email Account Setup.

      2. Click Authorize Access and sign in with your Microsoft credentials.

      3. When prompted, select the SMTP (Legacy) option.

      This ensures your Outlook account connects using the correct authentication method.

       

      4. Test the Connection

      1. Stay in Email & Settings > Email Account Setup.

      2. Click Test Delivery to confirm that the connection is working properly.

      If the test succeeds, your Outlook account should now send messages without any errors.


      Notes

      • This is a Microsoft-side setting that applies specifically to Office 365/Outlook accounts.

      • If you’re part of an organization, you may need your IT administrator to make the change for you.

      • Once SMTP AUTH is enabled, messages should send normally from your connected Outlook account.