Git credentialsEdit
On macOS, git config credential.helper defaults to "osxkeychain". The first time you use a tool like git-send-email and get prompted for a password, it will be stored in the keychain as an item of kind "Internet password", name "smtp.example.com", account "you@example.com", where "smtp://smtp.example.com:587", and access control "Confirm before allowing access" for the git-credential-osxkeychain executable.