The system was previously set to use Steven’s Comcast SMTP server. Sending a test email from Eagle failed, indicating authentication failure. I changed this to use the University of Washington’s email server for outgoing messages. Here’s how…
In the Synology Disk Station Manager (DSM):
Control Panel > Notifications
Service provider: Custom SMTP Server
SMTP server: smtp.washington.edu
SMTP port: 587
Username: myUWnetID@uw.edu
Password: myUWpassword