postfix apresentado -> said: 552 Message size exceeds fixed

quando vou enviar mensagem o meu postfix me apresenta esta messagem no log, como eu faço para resolver isso????
said: 552 Message size exceeds fixed limit
veja o log abaixo!!!!

Mar 23 12:57:14 internet postfix/qmgr[5522]: 4E40079FA8: from=<[email protected]>, size=15744145, nrcpt=2 (queue active)
Mar 23 12:57:14 internet postfix/local[6374]: 23B9A79F9D: to=<[email protected]>, relay=local, delay=11755, status=deferred (unknown user: "marcos&quot<IMG SRC="images/forum/icons/icon_wink.gif">
Mar 23 12:57:15 internet postfix/smtp[6378]: connect to mx1.hotmail.com[65.54.254.129]: Connection refused (port 25)
Mar 23 12:57:15 internet postfix/smtp[6375]: D3A0779FA2: to=<[email protected]>, relay=mx4.hotmail.com[65.54.254.151], delay=3285, status=deferred (host mx4.hotmail.com[65.54.254.151] said: 552 Message size exceeds fixed maximum message size)
Mar 23 12:57:16 internet postfix/smtp[6378]: 4E40079FA8: to=<[email protected]>, relay=mx1.hotmail.com[65.54.166.99], delay=2010, status=deferred (host mx1.hotmail.com[65.54.166.99] said: 552 Message size exceeds fixed maximum message size)
Mar 23 12:57:17 internet postfix/smtp[6377]: D3A0779FA2: to=<[email protected]>, relay=mx2.uol.com.br[200.221.4.42], delay=3287, status=deferred (host mx2.uol.com.br[200.221.4.42] said: 552 Message size exceeds fixed limit)
Mar 23 12:57:17 internet postfix/smtp[6379]: 4E40079FA8: to=<[email protected]>, relay=mx4.uol.com.br[200.221.4.30], delay=2011, status=deferred (host mx4.uol.com.br[200.221.4.30] said: 552 Message size exceeds fixed limit)

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