Here are the classes, structs, unions and interfaces with brief descriptions:

Aacl
AccessControl
Account
AccountClass
ActiveFilters
AdminGroup
AdminLimits
AdminUser
AllowRule
Axigen
Cli
ContactInfo
Debug
Dnr
Domain
DomainRegistration
Filters
FolderRcpt
FtpBackup
Group
Imap
ImapProxy
IntegratedFilters
LdapConnector
Limits
Listener
Log
MailList
Message
MigrationData
Mobility
Permissions
Pop3
Pop3Proxy
Processing
PublicFolder
Quarantine
Queue
Quotas
Report
Rpop
ScriptFilters
SendRecvRestrictions
Server
SmtpIn
SmtpOut
SocketFilters
SslControl
UdpListener
UserDb
Usermap
Webadmin
Webmail
WebmailAdvertising
WebmailData
WebmailProxy