In McNeil Inc. the voicemail system is configured to send email alerts when new voicemails are left for users. Users are complaining that they are only receiving voicemails, but not email alerts.
Which of the following is the most likely cause of this issue?
A.
Port 25 is not functioning on the email server.
B.
Port 53 is not functioning on the email server.
C.
Port 21 is not functioning on the voicemail server.
D.
Port 23 is not functioning on the voicemail server.