fix(newsletter): Improve newsletter sending route error handling and configuration #159

Job	Run time
Security & Code Quality	1m 14s
Test Suite	1m 0s
Database Tests	59s
Build & Performance	4m 7s
Enhanced Security Testing	4m 47s
Deploy to Staging	0s
Deploy to Production	0s
Performance Monitoring	0s
Rollback on Failure	0s
Performance Monitoring (Staging)	0s
	12m 7s

Provide feedback