macOS

  • macOS 10.10 (Yosemite) – 10.13 (High Sierra)
  • Intel Core processor that can run 64-bit applications
  • 4 GB of RAM (8 GB recommended)
  • 100 MB hard drive space for application files (excluding local message data)
  • Postbox runs in 64-bit mode on macOS



Windows

  • Windows 7, 8, and 10
  • Pentium 4 or newer processor that supports SSE2
  • 4 GB of RAM (8 GB recommended)
  • 100 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