Email send to Hotmail or Gmail and mail goes to junk/spam folder, it could be due to several reasons below:
1) IP not set with proper SPF or PTR records.
2) IP is blacklisted and has been classify as spamming IP.
3) There is high volume emails goes to Hotmail / Live Mail server, where the IP or source has been classify by Hotmail's users as Junk or Spam mail.
If any of the IP or hosting is no longer spam or its due to previously IP blacklist, Gmail and Hotmail filtering system may need some time (estimate about 3-7 days) to learn the email from your hosting as a legitimate emails.
Do request your gmail/hotmail user (recipient), mark your email as Not Junk or Spam for faster the respective spam filtering process to learn your email as not junk or spam.
For more information, you can check out from the link below:
Hotmail: [ http://mail.live.com/mail/junkemail.aspx ] --> SmartScreen
Gmail: [ https://support.google.com/mail/answer/81126 ] --> "Delivery"
KB; [ http://gmailblog.blogspot.com/2012/03/learn-why-message-ended-up-in-your-spam.html ]
If the problem still persists, kindly submit us a support ticket for further assistance.
