Exchange 2013 - DWG attachement (421 4.7.11 Message deferred )

We use MSExchange Server 2013 standard

and we have problem with recieving e-mails with .dwg attachment from everywhere. This messages are in theQueue

of Exchange server and always gives the error below:

We tried make ZIP files from DWG, but it is the same problem

Identity: CALLISTO\Submission\17763984736359
Subject: FW: Odesílání e-mailu: b.dwg, c.dwg, d.dwg, a.dwg
Internet Message ID: <4B6E309ADA622C43BD2121BC5010A40850F1F64E@SBS2011.jaz.local>
From Address: petrjedlicka@jaz.cz
Status: Opakovat
Size (KB): 7520
Message Source Name: SMTP:Default CALLISTO
Source IP: 81.201.49.168
SCL: -1
Date Received: 2. 6. 2014 11:59:24
Expiration Time: 4. 6. 2014 11:59:24
Last Error: 421 4.7.11 Message deferred. The attempt to extract text timed out., tenant -
Queue ID: CALLISTO\Submission
Recipients:  servis@uniservis-hasek.cz;3;0;421 4.7.11 Message deferred. The attempt to extract text timed out., tenant - ;0; it@jaz.cz;3;0;421 4.7.11 Message deferred. The attempt to extract text timed out., tenant - ;0;

Any IDEAS? Thanks