Introduction
WorldPosta Email service is based on Microsoft Exchange. Exchange’s mailboxes contain 3 types of data: Email messages, Contacts, Calendar entries.
These three types of data are synchronized between the server and the mail client (outlook or Thunderbird) after configuration to connect to the mailbox.
Exchange mailboxes can be accessed via many protocols:
(1) MAPI: (Messaging Application Programming Interface)

• Direct connection to the server;
• shared Inbox, Contacts, Calendar entries, Notes, Tasks and public folders;
• Server-side rules and alerts;
• Optional server-side spam management;

(2) POP: (Post Office Protocol)
Just send and receive Email, without MAPI Features
(3) POP/IMAP:
Contains only mail data. The functionality is more limited (compared to Exchange).
(For example, all the features available for an Exchange mailbox (via MAPI) are not supported)
You can access your mailbox via POP or IMAP protocols and also via Webmail
The following features are supported by WorldPosta:

• Forwarding
• Adding user to a Distribution List
• Auto-replies
• Hiding a mailbox from your address book
• Storage management

(4) OWA-Only:
Using OWA-only mailboxes is like using Exchange mailbox, with all hi its functionalities; you can access your Emails via Webmail (OWA) from any browser supported, and only via browser, that means no mail client
Note: you can connect your Outlook client to an OWA-only mailbox using IMAP/SMTP or POP/SMTP protocols or EWS.