I’m using the MailSystem.NET OS library for handling IMAP. I have a problem with my client program (written in c#). It polls the mail server using the IMAP library. It marks a message as deleted after adding it into the client db. However, I don’t necessarily want to remove the email physically as other clients won’t be able to read the email.
So I call DeleteMessage(1, false), which should MARK the email as deleted but since ‘expunge’ is set false it is not physically removed from the server.
If I open Thunderbird (a different client) and connect to the mailbox, sure enough the message has gone. However, my other client sees the message as still there. The message count shows 1. How do I make sure that when I return the message count from the ‘INBOX’ mail folder it only returns those that are not marked for deletion, i.e. those that have not already been read by the client program?
As Ivar mentioned in his comment, you can use UNDELETED to search the mailbox for messages. However, I found the “NOT DELETED” search flag to work better on the IMAP library I have been using.