Pop

Pop is an email client for the terminal that sends messages through either a text-based user interface or plain command-line flags. Running pop with no arguments launches the TUI. For scripting, the body can be piped in on stdin and fields passed as flags, for example pop < message.md --from ... --to ... --subject ... --attach invoice.pdf.

Delivery goes through Resend or SMTP. pop auth authenticates with Resend via OAuth, and a RESEND_API_KEY environment variable also works. For SMTP, set POP_SMTP_HOST, POP_SMTP_PORT, POP_SMTP_USERNAME and POP_SMTP_PASSWORD. Other settings include POP_FROM to pre-fill the sender and POP_SIGNATURE to append a signature. Message bodies are rendered from Markdown to HTML by default. POP_PLAINTEXT=true or --plaintext sends plain text instead, and --preview lets you review and edit a message before it is sent.

Pop is meant to be combined with other command-line tools. The README shows gum choosing the sender and recipient, crush run generating a body that is piped into pop, and invoice producing a PDF that pop --attach sends. For AI coding agents, pop skill prints a skill definition that can be written to a SKILL.md file, and pop install-skill installs it for Crush, Codex and other supported agents. It suits developers and shell-script authors who need to send mail from scripts or pipelines.

Installation

# via Homebrew
brew install pop

# via Go
go install github.com/charmbracelet/pop@latest

# via Nix
nix-env -iA nixpkgs.pop