First sorry but I do not know very well English.
Second try with this:
[SOLVED] Automatic IMAP/POP retrieval
I had the same problem and I solved by following this thread
especially
Let's check the account level:
zmprov ga
user@domain.com | grep zimbraDataSourcePollingInterval
Try setting the account level:
zmprov ma
user@domain.com zimbraDataSourcePollingInterval 15m