1

For hardware, the limit is at approx. 15,000 mail boxes due to the restricted resources. With virtual appliances, the limit may be increased by adding additional resources (please also refer to 4). In each case, the number of supported mail boxes can be increased as desired by cascading several appliances.

2

With an assumed average email size of 200 kByte

3

Since some resources in virtual environments are not comparable to physical ones (memory/ processors), they can be adapted as appropriate. The resources must be provided statically  by the host system (compare, for example, ESX Thick Provisioning).

Furthermore, it should be noted that the values mentioned are minimum requirements. Especially with other active features, such as the Protection Pack (PP), more resources may have to be made available at this point.

4

The maximum number of possible mailboxes can be increased by scaling processor cores and RAM. In practice, however, it has been shown that exceeding the maximum values mentioned above can hardly lead to any further increases. In this case, however, several appliances can be cascaded.

5

Depending on the size of the hard drive, up to 4 GB are used for the expansion of the "/tmp" partition.