Attachments should be used judiciously in email marketing. The common file formats for attachments include:
PDF: The most professional and widely accepted format for documents. PDFs are great for brochures, manuals, and other types of formal documentation. DOCX: Microsoft Word documents are also commonly used but ensure that recipients have compatible software to open them. CSV: Ideal for data files and spreadsheets. CSV files are lightweight and can be opened in various applications.