Try this:

declare@max_attachment_sizeint,-- in bytes

@average_rowsizeint,-- in bytes

@number_of_rowsint,-- used for the TOP in the dynamic select

@dynamic_selectvarchar(8000)-- dynamic select statement

select @max_attachment_size=paramvalue

from msdb.dbo.sysmail_configuration

where paramname = 'MaxFileSize'

select@average_rowsize=used_page_count*1024/row_count

from sys.dm_db_partition_stats

where object_id=object_id('sysmaintplan_log')

select @number_of_rows=@max_attachment_size/@average_rowsize

IF EXISTS(SELECT TOP 1 1 FROM [e009])

begin

select @dynamic_select='select top ' + convert(varchar(16),@number_of_rows) + ' * from [e009]'

exec msdb.dbo.sp_send_dbmail

@profile_name = 'Default',

@recipients = 'me@example.com',

@subject = 'warning',

@query = @dynamic_select,

@attach_query_result_as_file = 1,

@query_attachment_filename = 'warning.csv'

end