php sending email with the name in MX records and not with the hostname

php sending email with the name in MX records and not with the hostname

i just setup a mail server in the same server as my web server, in order
to send emails and not getting thrown in the Spam, i've configured a TXT
record for my SPF info and of course an MX record, the problem is when i
send an email it still classified as spam, and when i showed the original
message i found this :
Gmail : smtp.mail=root@nsxxxx.ovh.net
Hotmail : smtp.mailfrom=root@nsxxxx.ovh.net
i'de lik to now how can i send it with the name in my MX record, and how
to avoid spaming