Calendar Synchronization Agent EMWCSA.log contains errors -2147467259 (4352458)

CSA is logging the following information:

Started processing mailbox '/o=Enterprise/ou=ABC/cn=Recipients/cn=JohnD'.
Mailbox '' is marked as not switched.
Starting synchronization from E55 to E2K

CFolder::GetHiddenMessageBySubject Error -2147467259 The client operation failed. [Microsoft Exchange Server Information Store - [E_FAIL(80004005)]]

CFolder::SetExchSyncInfo Error 607 Cannot save last synchronization info.

Source mailbox (user account) disabled

There are many possible reasons for this error, two most common reasons are:

1. Source account is disabled.

2. Source or target mailbox is full and reached the size limit and this prevents the agent from placing the message.
If a limit is set in source then this limit setting will be copied to target. Target mailboxes will be always bigger then in source due to several factors, one of the main factors is the loss of single instance storage during mail migration.