macOS

  • macOS 10.13 through macOS 13
  • M1 or Intel Core processor that can run in 64-bit
  • 8 GB of RAM
  • 200 MB hard drive space for application files (excluding local message data)
  • Postbox runs in 64-bit mode on macOS



Windows

  • Windows 8 and higher
  • Pentium 4 or newer processor that supports SSE2
  • 8 GB of RAM
  • 200 MB hard drive space for application files (excluding local message data)
  • Postbox runs in 32-bit mode on 32-bit and 64-bit versions of Windows