Threshold email notifications not sent despite correct SMTP configuration

[somethingwithproof]

Description

Threshold alerts are not sending email notifications even when SMTP configuration is correct and test emails work. The threshold triggers correctly (visible in the log and UI), but the notification email is never delivered.

Steps to Reproduce

1. Configure SMTP settings in Cacti (Settings > Mail/Reporting)
2. Verify test email sends successfully
3. Create a threshold with email notification enabled
4. Wait for the threshold to trigger

Expected: Email notification is sent when threshold triggers
Actual: Threshold triggers (visible in logs) but no email is sent. No SMTP errors in log.

Environment

• Cacti versions: reported across 1.2.x releases
• Thold plugin: multiple versions affected
• Multiple reporters confirmed working SMTP with test emails but failing threshold notifications

Forum Reference

Originally reported at https://forums.cacti.net/viewtopic.php?t=62295