UNIX for Dummies Questions & Answers

Hi, maybe someone could help me.
This is the thing. I usually use the command "mail" on my scripts to send me info about the linux box, something like:
df -k | mail -s "disk usage" lalala@lalala.com.
This works fine in all the linuxes that sendmail is installed, but there is one with Postfix that doesn't work.
I think is 'cause the mail command is from sendmail and not from Postfix. If this is true, I wanted to know if Postfix has some command similar to "mail"

Thanks. (I hope my questions is clear enough)

Finally I checked the /etc/postfix/main.cf. There is a line that called inet_in terface and localhost was missing. So, if you need to send mails from the smtp server, you should use localhost and the lan interface.

sos long.