Problem with Reports - File to large

I get the error below when I try to send a report. I have sent reports in the past while testing out NetFlow with no issues, but recently I get an error message sent. This error happen when set to send zipped or as a pdf.

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EMAIL
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Dear User,

This is an automated mail generated by Netflow Analyzer Report Generation Engine.
Problem while sending the report.[ Problem could be of large File size

Report details:Report Type :Consolidated Report
Report Generation Time: Tue Nov 27 17:31:51 CST 2007
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Thanks,
NetFlow Analyzer