How to retrieve unread mails using IMAP c client feeds

Is there any way to retrieve only unread mails from specific person with email address person@gmail.com using IMAP C client Apis.

I know it can be done by using mail_search (unseen flag开发者_JAVA百科), but I think it would be more expensive to query every time. Please suggest a better way to do this.

If possible can you please post a sample program.

Thanks in advance. Regards Subbi

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search with unseen flag is the best option since any of the commands that you are going to fire will scan the entire mailbox in order to list down the unread mails. Have developed a imap server for a mailer and with my experirnce its not possible. But at clients end you can manage a map of mail states(like read forward replied..)