macOS

  • macOS 10.13 through 15
  • 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 through 11
  • 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