It sounds like you are experiencing an issue with sending emails from Windows 7 where the system is indicating that certain email addresses are invalid, even though they work fine on your phones and other computers. Here are a few troubleshooting steps you can try to address this problem: 1. Check Email Address Format: - Double-check the email addresses you are trying to email. Ensure there are no spaces, typos, or special characters causing the system to flag them as invalid. 2. Disable Antivirus/Firewall: - Sometimes, antivirus software or firewalls may interfere with email sending functionality. Temporarily disable them and try sending the emails again to see if the issue persists. 3. SMTP Server Settings: - Verify...