DTOs:
- EmailProfileDto: Profile data transfer object
- EmailAccountDto: Email account data transfer object
- EmailHistoryDto: Email history data transfer object
- EmailAttachmentDto: Attachment data transfer object
Dependencies:
- MediatR 14.2.0 for CQRS (Commands/Queries)
- AutoMapper 12.0.1 for entity-DTO mapping
- FluentValidation 12.1.1 for input validation
This provides the foundation for the application layer implementation.
