Parse Gmail with Python and mark all older than date as “read”

Question

Long story short, I created a new gmail account, and linked several other accounts to it (each with 1000s of messages), which I am importing. All imported messages arrive as

Answer 1

Based on Philip T.'s answer above and RFC 3501 and RFC 2822, I built some lines of code to mark mails older than 10 days as read. A static list is used for the abbreviated month names. This is not particularly elegant, but Python's %b format string is locale dependent, which could give unpleasant surprises. All IMAP commands are UID based.

import imaplib, datetime

myAccount = imaplib.IMAP4()
myAccount.login(, )
myAccount.select()

monthListRfc2822 = ['0', 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
                    'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
beforeDate = datetime.datetime.today() - datetime.timedelta(days = 10)
beforeDateString = ("(BEFORE %s-%s-%s)"
                    % (beforeDate.strftime('%d'),
                       monthListRfc2822[beforeDate.month],
                       beforeDate.strftime('%Y')))
typ, data = myAccount.uid('SEARCH', beforeDateString)
for uid in data[0].split():
    myAccount.uid('STORE', uid, '+FLAGS', '(\Seen)')

By the way: I do not know, why "-" had to be used as a date delimiter in the search string in my case (dovecot IMAP server). To me that seems to contradict RFC 2822. However, dates with simple whitespace as delimiter only returned IMAP errors.