Fix smtp email sending and connection issues

The connection issue for users using custom SMTPs has been resolved.

Improved Email Reliability: Eliminates protocol-related transport errors and ensures seamless connection with all supported SMTP providers.

Increased Deliverability: More stable email flows for transactional, onboarding, and marketing messages.

Fewer Support Cases: Reduces internal triage time caused by email send failures tied to low-level connection errors.