#Outlook0 discussing

Hi! Huan,

Please follow the below steps:

Installing the Salesforce Outlook Add-in (Mac)

• If you have Microsoft Outlook open, close it
• Navigate to the Office 365 website ‘Manage Add-Ins’ Page: (https://outlook.office.com/owa/?path=/options/manageapps)
• Find Salesforce in the add-in in the list and check the box in the Turn On column
• Wait about 15 to 20 seconds and then open Microsoft Outlook
• The Salesforce add-in should appear on your Outlook ribbon

Configuring the Salesforce Outlook Add-in

• Click on the Salesforce Outlook Add-in on the Outlook ribbon (toolbar) to open it
• If you’re using the web version of Outlook you can configure the add-in by clicking on the Salesforce Outlook icon
• Make sure ‘Production’ is selected for the Environment
• Click on “Log In To Salesforce”
• Click on ‘Use Custom Domain’
• You will be logged into Salesforce inside Outlook the add-in
• Once you’ve activated and configured the Salesforce add-in it will be active and configured in all versions of Outlook, both desktop and web versions.

I hope you find the above solution helpful. If it does, please mark it as the Best Answer to help others too.   

Thanks and Regards,  

Suraj Tripathi

I am assuming, in the org below steps have been followed

1. From Setup, in the Quick Find box, enter Send through External Email Services, and then select Send through External Email Services.
2. Select either Send through Gmail or Send through Office 365.
3. From Setup, enter Deliverability in the Quick Find box, then select Deliverability under Email.
4. Set the access level for sending email to All email.

In that case, for your ask.. we cannot disable that Option of Send through Salesforce. May be try to raise a case with Salesforce support and check if they can disable for the Org.

an alternative way is.. (since the salesforce option will exist).. you can try to enforce users for Office365 via training as well as explore Email Relay services. This needs some work but i guess it will work as it requsts salesforce to relay all emails via office 365. Link as below

https://help.salesforce.com/s/articleView?id=000337644&type=1

Hi @Gwenn Ferguson,

To troubleshoot the issue, you may want to check the following:

1. Check if the Lead record exists in Salesforce and if the email address associated with the Lead matches the email address in the email being attached.
2. Verify if there are any customizations or configurations in your Salesforce instance or Outlook integration that may be causing the issue.
3. Check if the user who is trying to attach the email has the necessary permissions to access and modify the Lead record.
4. Review the error message in the URL and try to identify the cause of the issue.
5. If the issue persists, you may want to contact Salesforce support or your organization's Salesforce administrator for further assistance.

@Jazmine Moore

Do you see any errors when you click on the Troubleshoot option in Outlook Integration panel? So navigate to the email where you are getting this error and then click on troubleshoot, see if you are getting any error there.