if line.starts_with("* LIST") {
if let Some(last_slash_pos) = line.rfind('/') {
let mailbox_name = line[(last_slash_pos + 1)..]
if line.starts_with("* LIST") {
if let Some(last_slash_pos) = line.rfind('/') {
let mailbox_name = line[(last_slash_pos + 1)..]