The GroupWise Post Office Agent (POA) delivers messages to users’ mailboxes, connects users to their post offices in client/server access mode, updates post office databases, indexes messages and documents, and performs other post office-related tasks. You must run at least one POA for each post office.
The following sections help you understand the various functions of the POA:
Using client/server access mode, the GroupWise client maintains one or more TCP/IP connections with the POA and does not access the post office directly. Consequently, the performance of the POA in responding to requests from the GroupWise client directly affects the GroupWise client’s responsiveness to users. To provide the highest responsiveness to client users, you can configure a POA just to handle client/server processing. See Section 38.1.3, Configuring a Dedicated Client/Server POA (Windows Only).
When using client/server access mode, the GroupWise client can be configured to control how much time it spends actually connected to the POA.
In Online mode, the client is continuously connected.
In Caching mode, the client connects at regular intervals to check for incoming messages and also whenever the client user sends a message. Address lookup is performed locally. Caching mode allows the POA to service a much higher number of users than Online Mode.
In Remote mode, the client connects whenever the client user chooses, such as when using a brief modem connection to download and upload messages.
For more information about the client modes available with client/server access mode, see Using Caching Mode
and Using Remote Mode
in the GroupWise 2012 Windows Client User Guide
Client/server access mode also allows users to access their GroupWise mailboxes from POP and IMAP clients, in addition to the GroupWise client. See Section 36.2.3, Supporting IMAP Clients.
In client/server mode, the POA is enabled for secure SSL connections by default. If necessary, you can configure the POA to force SSL connections with all clients. See Section 36.3.3, Securing the Post Office with SSL Connections to the POA.
Messages from users in other post offices arrive in the local post office in the form of message files deposited in the POA input queue. See Section 35.3.4, Agent Input/Output Queues in the Post Office.
The POA picks up the message files and updates all user and message databases to deliver incoming messages in the local post office. To provide timely delivery for a large volume of incoming messages, you can configure a POA just to handle message file processing. See Section 38.2.2, Configuring a Dedicated Message File Processing POA (Windows Only).
In addition to client/server processing (interacting with client users) and message file processing (delivering messages), the POA:
Performs indexing tasks for document management.
Performs scheduled maintenance on databases in the post office.
Monitors and manages disk space usage in the post office.
Restricts the size of messages that users can send outside the post office.
See Section 36.2.7, Restricting Message Size between Post Offices.
Primes users’ mailboxes for Caching mode.
Performs nightly user upkeep so users do not need to wait while the GroupWise client performs it; also creates a downloadable version of the GroupWise Address Book for Remote and Caching users.
Provides LDAP authentication and LDAP server pooling.
See Section 36.3.4, Providing LDAP Authentication for GroupWise Users.
Prevents unauthorized access to the post office.
Tracks the GroupWise client software in use in the post office.
See Section 36.2.5, Checking What GroupWise Clients Are in Use.
Automatically detects and repairs invalid information in user databases (userxxx.db) and message databases (msgnnn.db) for the local post office by using an efficient multi-threaded process.
See Section 38.4.1, Adjusting the Number of POA Threads for Database Maintenance.
Automatically detects and repairs invalid information in the post office database (wphost.db).
Automatically detects and repairs damage to the guardian database (ngwguard.db) in the post office.
Updates the post office database whenever GroupWise users, resources, post offices, or other GroupWise objects are added, modified, or deleted.
Replicates shared folders between post offices.
Executes GroupWise client rules.
Processes requests from GroupWise Remote users.