Welcome, if you would like to post a comment please register.
We also encourage you to explore all things Zimbra with our team and members of the community.
I have a client who just set up the connector for Zimbra, and it took at least 15mins to sync his tasks. Although it only takes 1-2 for his calendar, which has over 2000 appts in it.
Noticed this with windows mobile phones. The tasks would take days to sync if we let it.
It's got to be a mobile issue. Tasks are generally less complicated than calendar items, but the processing in ZCO is very similar. I have never seen Tasks take a lot of time.
Bugzilla
Wiki
Source
Outlook Task Sync 
Linear Mode
