MailEnable Professional Guide
Messaging Manager - Administration
Administration > Messaging Manager > Messaging Manager - Administration

Settings Explanation
New mailboxes have size limit Configures the default quota for mailboxes, so every new mailbox created will have a quota configured. This only affects mailboxes that are created through the administration program. It does not set the default quota for new mailboxes created with 3rd party applications or ones that use the MailEnable API.
Automatically create an email address for each domain, with every new mailbox created. If there are several domains in a post office and this setting is selected, then every time a mailbox is created in a post office a mail address or address mapping will be created for each domain for the mailbox. This only affects mailboxes that are created through the administration program.
Populate Asynchronously When this option is selected the list views in the administration program will update in a background process. This may make the display slower to complete, but you may be able to access the contents earlier.
When displaying the mailbox list, disk usage is determined:

Use this option to set the size calculation method for listing mailboxes. The available options are:

Calculate sizes (slow):

This option will set the calculation method to calculate the sizes of of the mailbox folders when accessing the mailbox list. This can have an impact on performance if the list of mailboxes is large and each mailbox contains large amounts of messages.

Use precalculated sizes (fast): 

Will use the pre calculated size reported within the DIRSIZE.tmp file. This file contains the current disk usage of the folder it is in. If the file is over 20 minutes old, then it will be updatred.

Dont show sizes (fastest):

This option will disable the calculation method and not display any sizes within the mailbox list. The size column in the mailbox list will show NA.

Virtual list limit:

MailEnable will try to load all the display items in the administration program into memory to sort and view the lists. This can cause long delays for large numbers of mailboxes. This option determines how many mailboxes need to be in a postoffice before a virtual list is used.

Note: If using Tab Delimited files (default) configuration storage, mailbox lists after this size will not be sorted.