How to only get new mail

Hi,

I met a problem about only get new mail,  please provide some help,  Thanks.

I use getmail 4.48.0,  and here is my getmail.rc

[retriever]
type = SimpleIMAPSSLRetriever
server = ***
port = ***
username = ***
password = ***
mailboxes = ALL

[destination]
# we configure Patchwork as a "mail delivery agent", in that it will
# handle our mails
type = MDA_external
path = /opt/parsemail.sh
allow_root_commands = true

[options]
verbose=1
# retrieve only new emails
read_all = false
# do not add a Delivered-To: header field
delivered_to = false
# do not add a Received: header field
received = false


And I use crontab to run getmail per 5 minutes  by 'getmail --getmaildir=/opt/getmail/ --idle INBOX".

I hope to retrieve mail by getmail and the mail send to parsemail.sh to parse. but I only hope to
get new mail or maybe get the same mail only one time.


but the actual result is that, there is a mail A, it will be retrieved everytime crontab run "getmail --getmaildir=/opt/getmail/ --idle INBOX".
so the mail A will be parsed per 5 minutes. but I only want to parse one time. As I thought, the first time, it is new mail, I want to retrieve
it.  but the second time, I have retrieve it once, it should have been seen, and not been retrieved. but actually, it now work as this.


I have read the doc of getmail, it says read_all = false can retrieve only new mails.  but it not work as expected.


Can you help to point out where I am wrong?  Thanks.


Should I also add delete = true in the [options] section,  in this way,  after the mail is retrieved one time and deleted, it will be take as seen,
and will no be retrieved in second time?



-- 
BRs

Sandy(Li Changqing)