“An attempt was made to access a socket in a way forbidden by its access permissions” while using SMTP

Question

I am trying to send an SMTP email when certain values in database crosses its threshold value.

I have already allowed ports 25,587 and 465 in the Windows firewall an

Answer 1

Please confirm that your firewall is allowing outbound traffic and that you are not being blocked by antivirus software.

I received the same issue and the culprit was antivirus software.