Hello Everyone,
Sometime, it happens that you are getting error - 100502 in outlook for sending/receiving function. One of the reason behind this error will be your ISP's IP might be blocked in Firewall due to incorrect POP3 or SMTP attempts.
You can check your ISP's IP by using this link - http://www.checkip.com or Serch this keyword in Google "What is my IP address" and contact your Hosting provider.
Hope, this solution should work for the issue.