Overview

This article answers the query: Why are messages missing when viewing an archived mailbox via IMAP (Internet Message Access Protocol) server?

Information

Refer below for a greater understanding of how IMAP works and why this may be happening.

Understanding IMAP Synchronization Process

Generally, when the IMAP server configuration is first enabled, the mailboxes that you connect to will not contain all of the expected emails. This is because a synchronization process is performed on the backend to pull information about each mailbox and each archive store depending on the range specified for the number of emails to display.

By default, the IMAP accounts will display 12 months of email.

As messages are synchronized, they will begin to appear via the IMAP connection. Depending on the number of users and size or archive, it can take several hours to see all 12 months of email with the IMAP connection to the archive mailbox.  

The larger the interval set, the longer it can take to display all messages of the archived mailbox. In general, the process should take no more than 24-48 hours, and in most cases, far less time than that.

Start Date of Archive Stores

Also, note that the 'maximum months to show in mail clients' is not directly calculated against every single email. GFI Archiver checks against the Start Date of each archive store and only exposes emails if the Start Date falls into the configured amount of months (plus the set interval of the archive store schedule).

To explain this, let's assume that you ran GFI Mail Archiver 2011 or older and emails got archived into archive store(s) which span more than one year significantly:
 

Let's assume:

• Maximum months to show in mail clients: 12 months
• Archive Store Schedule: bi-monthly (every two months)
• Today's date: 15/12/2012

In this scenario, no email would be exposed via IMAP as the Start Date of no archive store falls into the 14 (12 + 2) months.