TL:DR; Java Mail library.
Java Mail library. This is a small java package that can send and receive emails. Including MIME and attachements.
Java package/API to send and receive faxes. It can be used to send and receive faxes from your java applications to any group 3 facsimile machine. It requires a class 1 faxmodem, it can fax images, text, html and pdf files. Source code is available.
The Java Excel Connector (JEC) allows Java developers to access the Excel application, read, create or modify Excel workbooks and charts.
Barcode java bean and servlet. Supports all major 1D&2D symbologies: EAN, UPC, code 128, code 39, PDF417, codabar ,RSS14, maxicode, aztec, micro and macro pdf 417, datamatrix....