Salesforce for Outlook (SFO) Cannot Connect to login.salesforce.com

This article explains how to resolve the Salesforce for Outlook (SFO) connection failure when the setup wizard cannot reach login.salesforce.com. Resolution requires involvement from your organization's IT team.
Step 1: Contact Your IT Team
This is not a Salesforce platform issue. Contact your internal IT team and ask them to:

1. Review whether security software or Group Policy is blocking the SFO application (SfdcMsOl.exe) from accessing external URLs.
2. Allowlist the SfdcMsOl.exe file in your organization's security software.
3. Reboot the machine after allowlisting, as Group Policy changes may require a restart to take effect.

Step 2: Use Fiddler to Diagnose Network Traffic
If the issue persists, your IT team can use Fiddler to capture and analyze network traffic to identify what is blocking the connection. Fiddler is a free third-party network debugging proxy tool that intercepts HTTP/HTTPS traffic between applications and the internet.
Ask your IT team to install Fiddler and review the captured logs to identify which network request is failing. They can also check Firewall logs for blocked connections to Salesforce endpoints.