Opening an email attachment on Android involves accessing a file sent as part of an email message and viewing or working with it using apps installed on your device. When you receive an email with a file (like a document, image, or spreadsheet) attached, it's typically represented by a downloadable icon within the email body. Tapping this icon downloads the file if needed and then prompts your device to open it using an appropriate application. This differs from opening files already stored locally on your device.

To open an attached PDF report in the Gmail app, tap the PDF icon, then select "Open with" and choose your preferred PDF reader app, like Adobe Acrobat or Google PDF Viewer. To edit an attached Excel spreadsheet from Outlook, tap the .xlsx file icon, choose "Open with," and select Microsoft Excel or Google Sheets. Common apps used include native viewers (Gallery for images) and third-party software like Word, Excel, or specific document readers for various file formats.

The main advantage is instant access to important documents directly from your email without manual transfers. However, limitations include needing compatible apps installed to open specific file types and the potential for large files to take time to download. Always ensure attachments come from trusted sources due to security risks. Future integrations might further streamline cloud-based file access directly from email clients.