items to fetch from message(s) as string (if only one item) or array of strings
$from
—
object
message for items or start message if $to !== null
$to
—
object
if null only one message ($from) is fetched, else it's the last message, INF means last message available
Returns
string|array
if only one item of one message is fetched it's returned as string if items of one message are fetched it's returned as (name => value)
if one items of messages are fetched it's returned as (msgno => value)
if items of messages are fetched it's returned as (msgno => (name => value))