The Main Reason: Cost and Abuse Control
Running disposable email infrastructure costs money. Short windows reduce storage needs and help limit abuse patterns.
Other Operational Reasons
• reduced server load
• easier inbox cleanup
• lower moderation burden
• simpler anti-spam enforcement
User Impact
Short limits work for instant OTP tasks but fail for delayed confirmations, trial reminders, and staged verification flows.
Better Alternative
Services that offer configurable duration provide more flexibility while still protecting user privacy.
Bottom Line
The 10-minute model exists for operational efficiency, not because it is always best for user workflows.