Hello i am new in this Forum and i am not sure is here is the correct forum to do my question... but here is going...we have installed zimbra and when we upgrated it we have started to have problems on receive mail and send mails. Some customer receive our mails but other don't, other don't receive our mails but we receive their mails and other receive mails from us but we don't from them. I create a whitelist but still doesn't work. So please help to solve this problem