Emails sends to hotmail account domains reach the recipient as SPAM the first time

Emails sends to hotmail account domains reach the recipient as SPAM the first time

Every time i send an email to a Hotmail domain it is flagged as SPAM or located in the JUNK folder. If the user finds the emails and watch it, the next time it arrives normarly. Looks like the ZOHO SMTP Servers that the company uses for the free Zoho users has been included in the black list by Microsoft (Outlook).