I have some doubts:

1.How to send mail through command propmt

note: I have installed sendmail but i am not able to send mail through cmd prompt

2.Hot to send sms through command prompt

note: I have installed mailtx but i am not able to send sms to my mobile(service privider: vodafone)

have you edited /etc/mail.rc? Typically you need to add smtp servers and relevant settings there for mailx to work..

The word "doubt" and the word "question" mean two different things. You don't tell us what version/distro of Linux you're using, and say that you've installed sendmail, but don't tell us the command you're using to send mail, or what errors/messages you're getting when you try.

Since you installed sendmail, did you configure it??? Unless sendmail knows where to send messages along to, there's nothing it can do. Are you using this on a company network, or at home? Have you configured a smarthost/relay server to handle the mail further upstream from you?
Again, unless you have a working mail system already, using any mail programs is not going to work. And where did you get the mailtx program, and how did you install it? What are you typing in to try to run it, and what are the results?