
Explanation:

Transport Control Protocol(TCP), User Datagram Protocol (UDP) ports, and Protocol Numbers are important to TCP/IP networking, intranets, and the Internet. Ports and protocol numbers provide access to a host computer. However, they also create a security hazard by allowing uninvited access. Therefore, knowing which port to allow or disable increases a network's security. If the wrong ports or protocol numbers are disabled on a firewall, router, or proxy server as a security measure, essential services might become unavailable.
TCP port 587 is an outgoing SMTP Mail port (TLS/Start TLS Port). Used by various outgoing mail servers as an alternative to port 25.
TCP port 443 is used for Audio, video and application sharing sessions as well as data sharing sessions.
RTP/UDP port 50020-50039 must be used for outbound video sessions.
RTP/UDP port 50000-50019 must be used for outbound audio sessions.
References:
https://support.office.com/en-us/article/Office-365-URLs-and-IP-address-ranges-8548a211-
3fe7-47cb-abb1-355ea5aa88a2?ui=en-US&rs=en-US&ad=US
https://www.speedguide.net/port.php?port=587