Zimbra Standard Edition or Zimbra Professional Edition provide Blackberry integration. Zimbra Standard or Professional Edition provides Blackberry integration. This requires a Blackberry Enterprise Server (BES) or BES Express Server (free). Also requires Zimbra BES Connector, available as a separate download from zimbra.com. For more details and documentation see www.zimbra.com/support/documentation/zcb-documentation.html
Zimbra Standard Edition or Zimbra Professional Edition provide Windows Mobile phone integration.
No, there is no extra cost to deploy additional Zimbra servers. You can have as many Zimbra servers as you require. Licensing is based on the total number of mailboxes in your organisation.
Zimbra at this point in time do not officially support Centos. However, Agileware and many others in the Zimbra community have large production Zimbra deployments on Centos which are operating perfectly. As explained on the Centos website: “CentOS conforms fully with the upstream vendors redistribution policy and aims to be 100% binary compatible”. There is a Request for Enhancement with Zimbra to official support Centos, see this Official Support for ZCS Network Edition on CentOS RFE #23487. For more details on this topic, see Zimbra CentOS support posts.