linux - Use crontab job send mail, The email text turns to an attached file which named ATT00001.bin

I want to analysis some data in one linux server,then send the it as Email text to my Email account , But when i execute this shell scripts in shell command, It works well, Weird is that when i put all the procedure into crontab job, The Email text will turns to an attached file, Can someone help?

#* * * * * sh -x /opt/bin/exec.sh >> /opt/bin/mailerror 2>&1

/* exec.sh */
#/bin/sh
cd /opt/bin
./analysis.sh > test
mail -s "Today's Weather" example@example.com < test

But when i execute exec.sh in shell command line directly, The Email will get text, Can someone explain it for me, grate thanks.