def sanitize_filename(filename)
  filename = filename.strip
  sanitized = filename.gsub(/[^a-zA-Z0-9_]/, "_")
  sanitized.gsub!(/_+/, "_")
  sanitized.gsub!(/^_+|_+$/, "")
  sanitized
end

def sanitize_rcptname(filename)
  filename = filename.strip
  sanitized = filename.gsub(/[^a-zA-Z0-9_\.]/, "_")
  sanitized.gsub!(/_+/, "_")
  sanitized.gsub!(/^_+|_+$/, "")
  sanitized
end