Initial commit: Cross-platform email migration script

- Add Python script for IMAP-to-IMAP email migration
- Support for preserving folder structure, flags, and dates
- Configurable via environment variables (.env file)
- Batch processing with progress reporting and error handling
- SSL/TLS support for secure connections
- Folder filtering capabilities (include/exclude)
- Comprehensive logging system
- Works natively on Linux and macOS without dependencies
- Include .env.template for easy setup
- Add comprehensive README with setup instructions

.env.template

@@ -0,0 +1,27 @@
+# Source IMAP Server Configuration (Host Europe)
+SOURCE_IMAP_SERVER=
+SOURCE_IMAP_PORT=
+SOURCE_IMAP_USE_SSL=
+SOURCE_EMAIL=
+SOURCE_PASSWORD=
+
+# Destination IMAP Server Configuration (Securehost.de)
+DEST_IMAP_SERVER=
+DEST_IMAP_PORT=
+DEST_IMAP_USE_SSL=
+DEST_EMAIL=
+DEST_PASSWORD=
+
+# Migration Settings
+TEMP_DOWNLOAD_DIR=
+LOG_LEVEL=
+BATCH_SIZE=
+PRESERVE_FLAGS=
+PRESERVE_DATES=
+
+# Optional: Folder filtering (comma-separated list, leave empty for all folders)
+INCLUDE_FOLDERS=
+EXCLUDE_FOLDERS=
+
+# Connection timeout in seconds
+IMAP_TIMEOUT=