send mail is not going to outlook mail
in my website, i have to send mail to other mailers where sent mail is going to gmail and yahoo. but it is not received by outlook mail. in other words, when i send mail to yahoo or gmail then it is received successfully but when i send mail to outlook then message on screen in my website shows that it is sent successfully but it is not received by outlook. i have checked junk and spam folders in outlook but mail is not received. please help me. i am using php coding and lamp server.