imap command 잘 아시는 초 고수분 ㅡㅡ;

* OK [UIDVALIDITY 1080400620] UID validity status
* OK [UIDNEXT 1080479657] Predicted next UID

위 두 문장 입니다.

1080479657 가 next UID 라면 현재 UID 는 1080479656 이란
이야기 인지...

Unique identifiers
are assigned in a strictly ascending fashion in the mailbox; as each
message is added to the mailbox it is assigned a higher UID than the
message(s) which were added previously. Unlike message sequence
numbers, unique identifiers are not necessarily contiguous.

The next unique identifier value is the predicted value that will be
assigned to a new message in the mailbox. Unless the unique
identifier validity also changes (see below), the next unique
identifier value MUST have the following two characteristics. First,
the next unique identifier value MUST NOT change unless new messages
are added to the mailbox; and second, the next unique identifier
value MUST change whenever new messages are added to the mailbox,
even if those new messages are subsequently expunged.

Note: The next unique identifier value is intended to
provide a means for a client to determine whether any
messages have been delivered to the mailbox since the
previous time it checked this value. It is not intended to
provide any guarantee that any message will have this
unique identifier. A client can only assume, at the time
that it obtains the next unique identifier value, that
messages arriving after that time will have a UID greater
than or equal to that value.

그리고... 여기서 메일을 부를때 헤더만 출력할때

a00 UID FETCH 1:3,7 (FLAGS UID RFC822.SIZE BODY.PEEK[HEADER.FIELDS (Date To Cc From Subject X-Priority Content-Type)])

뭐.. 위와 같이 부르는데...
UID FETCH 다음에 나오는 숫자가 좀 이해가 안갑니다.
start num:end num 아닌가요?

sequence-set = (seq-number / seq-range) *("," sequence-set)
; set of seq-number values, regardless of order.
; Servers MAY coalesce overlaps and/or execute the
; sequence in any order.
; Example: a message sequence number set of
; 2,4:7,9,12:* for a mailbox with 15 messages is
; equivalent to 2,4,5,6,7,9,12,13,14,15
; Example: a message sequence number set of *:4,5:7
; for a mailbox with 10 messages is equivalent to
; 10,9,8,7,6,5,4,5,6,7 and MAY be reordered and
; overlap coalesced to be 4,5,6,7,8,9,10.