Open Office files now supported

By popular demand, PostalMethods now supports Open Office file types for sending letters!

Supported file extension are:

ODT - "Writer" text files
ODS - "Calc" spreadsheets
ODP - "Impress" presentations
ODG - "Draw" drawings
ODM - "Writer" master documents
ODF - "Math" formulas

This expands our existing list of supported file types that can sent through the PostalMethods Web-to-Postal service.