Add env.example with all Docker environment variables

env.example

@@ -0,0 +1,37 @@
+# MCP Email Server - Docker Environment Variables
+
+# Logging
+LOG_LEVEL=INFO
+
+# IMAP (incoming mail)
+IMAP_HOST=imap.example.com
+IMAP_PORT=993
+IMAP_USE_SSL=true
+IMAP_USERNAME=
+IMAP_PASSWORD=
+
+# SMTP (outgoing mail)
+SMTP_HOST=smtp.example.com
+SMTP_PORT=587
+SMTP_USE_TLS=true
+SMTP_USE_SSL=false
+SMTP_USERNAME=
+SMTP_PASSWORD=
+SMTP_FROM=
+
+# Optional default CC/BCC (comma-separated)
+DEFAULT_CC=
+DEFAULT_BCC=
+
+# Business / triage context
+BUSINESS_DESCRIPTION=
+PERSONNEL_JSON=[]
+
+# Scheduled send (seconds between checks)
+SCHEDULED_SEND_INTERVAL=10
+
+# CalDAV / CardDAV (e.g., Nextcloud)
+DAV_BASE_URL=
+DAV_USERNAME=
+DAV_PASSWORD=
+DAV_VERIFY_TLS=true