We have a lot of thunderbird clients that I'd like to migrate to Zimbra Desktop. Those clients usually handle part of their mails using imap on the zimbra server and part in their local folders as mbox files. I'd like to import those local mbox files to the local folders in zimbra desktop.
In order to get them into zimbra, I did two things:
1. I installed the perl tool mb2md to transform the mbox folders into maildir format.
2. I wrote a bash script which transforms the maildir structure generated by mb2md into an importable tgz file that can be imported using zimbra desktop at "Preferences" -> "Local Folders" -> "Import/Export".
This works nicely. Unfortunately, the "received date" as shown in zimbra desktop's mail list is the date of import instead of the actual date the mail was received. I already searched the forum for a solution and found a promising header extension, X-Zimbra-Received:, but injecting that header to each mail with the same value as the Date: Header didn't change anything.
Any suggestions on know how I could make zimbra desktop keep the original date for the imported mails? Btw: I do not want to use imap, because that would take too much time for each import. I'd also prefer not to alter zimbra's database.