如何从IMAP服务器获取最近的10条消息？

Question

I use imaplib2 library to search the last 10 messages with such command:

imap_client.search(None, '{}:{}'.format(last_uid, last_uid - 9))

But to get last_uid I need exec every time command like this:

imap_client.select("INBOX", readonly=True)

to get last UID.

Are the any ways to:

1. get last UID without select() command fetch last 10 messages
2. without last UID. Maybe there are any search criterias like 'LAST' or '-10:'?

I can not exec command like this client.search(None, 'ALL') , because IMAP server have more than 50K messages.

Answer 1

You can get the last UID using the STATUS (UIDNEXT) command. However, you have to select the mailbox in order to retrieve messages, and when you issue SELECT, you'll get a message count back, which the Python imaplib's select returns.

So all you need is:

(status, response_text) = mailbox.select("inbox")
# response_text usually contains only one bytes element that denotes
# the message count in an ASCII string
message_count = int(response_text[0].decode("ascii"))

and then you can fetch the messages by index from message_count - 9 through message_count .

Note that messages are index starting at one.

Answer 2

For any future travelers who seek an answer to this, I came up with code from the hint given by @arnt.

svr = imaplib.IMAP4_SSL(server)
if svr.login(user=user, password=password):
    print('User ' + user + ' logged in successfully.')
else:
    print('Login for the user ' + user + " was denied. Please check your credentials.")

x = svr.select('inbox', readonly=True)
num = x[1][0].decode('utf-8')
#from here you can start a loop of how many mails you want, if 10, then num-9 to num
resp, lst = svr.fetch(num, '(RFC822)')
body = lst[0][1]
email_message = email.message_from_bytes(body)

For me this was quite handy as I was accessing an email with more than 67000 emails in it.