Hello. We are migrating, via our provider, from a Linux imap server to a Zimbra NE install. The main thrust of the migration will be a couple of imapsyncs. One a couple weeks in advance and then another one when the actual migration occurs. We have read the migration docs, but are confused about how to handle our situation. Like many places, we have a split of webmail only users and fat client users that may or may not leave mail on the server.
1. Some users use fat clients (Outlook, Eudora, and Thunderbird). Users mostly keep mail on the server, but they control that option themselves to stay under quota. We will sync their old email to the Zimbra server. My concern is that once they connect to the Zimbra server their fat client will download all of their messages again. The email client will see the connection as a new server and download all of the old messages. This is unacceptable, as it would result in thousands of duplicates for some users. How do we avoid this? Everyone seems to be using imapsync with Outlook. Are we missing something here? Some of our users have huge mailboxes.
2. Some users use webmail only. They should be fine after the imapsync.
imapsync sets the READ flag on the mails it migrates.
if you do everything correctly then these READ/Un-READ flags will get transferred correctly and your POP/IMAP fat clients will not download the mail again.
Thank you so much for that info. Is there a specific option to use with imapsync that we need to use to cause this?
hi..please search the fourms for "imapsync" and you will see lots of things people have already tried which will help you.
Actually, we didn't have much luck with that, as different people espouse different switches. Also, can someone clarify the "read" flag. The issue is that Outlook will think the messages have not been downloaded by it. This is POP, not IMAP, and the clients have been set to leave mail on the server. So they have downloaded the messages already but they remain on the server. Then imapsync copies them to the new server. The client connects, but this is a "new" server to Outlook so it redownloads the messages.
We ran into this in testing. It seemed to occur even after a different test client had downloaded the messages. The concern is that if leave mail on the server is checked, multiple clients can download the same mail. For example, I can download my messages on a home pc and then re-download the messages again at work with my work pc. The fact that they have been downloaded once does not stop the work pc from downloading the messages. I apologize for my confusion on this and thank you for your assistance. Hours of searching the internet and forums have not been that helpful on this.