Export to mailbox failed

Dear,

We try since many days to export archive ( 13 years emails and documnets) , as the mount of data is huge , we tried to export by year.

The problem that for some of them, the export is aborted after exporting a first quantity. the error messages do not give the source of it.

the file below :

Export Archive Report File
Start date & time: 07/12/2017 11:33:46

Export Settings:
---------------------------------------
=> The source archive and destination mailbox are listed below.
=> Age filter start date & time: 01/01/2013 00:01:00
=> Age filter end date & time: 31/12/2013 23:59:59
=> Retention Category filtering of archived items is off
=> Folder filtering of archived items is off

Report file: D:\Program Files (x86)\Enterprise Vault\Reports\Export_20171207113344.txt

Source Archive for export:
---------------------------------------
ROUISSI Mariam

Destination mailbox:
---------------------------------------
Evault_Export

Time log:
---------------------------------------

Time: 11:34:09
Export of archive username Failed
Reason: Operation aborted

End time: 11:34:09

Results Summary:
---------------------------------------

Username : Failed
Operation aborted
Storage server: XXXXXXXSerur
Exported = 0; Failed = 1; Remaining = 3759 (99%)

Number archives processed: 0
Number archives being processed: 0
Number archives part processed: 0
Number archives not processed: 0
Number archives failed: 1

{end of report}