Are you running Norton 360?
Did you temporarily disable Norton Firewall…as test?
Did you reset Norton Smart Firewall?
Did you Restart (not Shut down) your machine?
Did you reset your router?
All: One other thing to note is disabling SPA settings in Outlook.
AI Overview
No, you should not enable Secure Password Authentication (SPA) for Comcast email in Outlook. Comcast/Xfinity uses standard SSL/TLS authentication. Enabling SPA often causes connection errors. Ensure “Require logon using Secure Password Authentication (SPA)” is unchecked. Use (SMTP) with SSL/TLS enabled instead.
I was able to create a rule in the Norton firewall to enablw ports 993 and 587. After that, I was able to access Comcast IMAP dervers. Why would Norton firewall block ports that are used by every email service app?
By default, Norton 360 does not block ports 993 (IMAP) and 587 (SMTP) for standard email traffic. However, because these ports handle encrypted connections (SSL/TLS or STARTTLS), Norton cannot scan the data passing through them. This often leads to a misconception that the ports are blocked, as the Email Protection and Anti-Spam features cannot be enabled for them.
Key Details on Norton and Email Ports
Port 993 (IMAP): This is the standard port for secure incoming mail. Norton allows this traffic, but its Email Protection feature cannot scan it because the content is encrypted.
Port 587 (SMTP): This is the modern secure port for outgoing mail submission. While the Norton Smart Firewall allows this traffic by default, you cannot add it to the “Protected Ports” list in Norton settings for antivirus scanning.
Encrypted Traffic Limitation: Norton 360’s email scanning is generally restricted to non-encrypted ports like 110 (POP3) and 25 (SMTP).
Safety Baseline: Even though Norton doesn’t scan the encrypted email stream, you remain protected by Auto-Protect, which scans any email attachments the moment they are accessed or saved to your disk.
Troubleshooting Connectivity Issues
If your email is failing on these ports while Norton is active, it is likely due to a configuration conflict rather than a default block.
Temporarily Disable Firewall: As a test, briefly disable the Norton Smart Firewall to see if connectivity returns. If it does, you may need to reset your firewall rules or create a custom allow rule.
Email Protection Settings: In some cases, the “Scan inbound/outbound emails” setting can cause timeouts on secure connections. Try turning this off under Settings > Antivirus > Email Protection to see if it resolves the issue.
Network Trust Level: Ensure your network is set to “Private” in Norton settings. Public profiles have stricter default rules that might restrict certain communications.