Solution 1 : Go to Outgoing server settings > put checkmark on "My outgoing server requires authentication"

Solution 2 : SMTP sever runs on port 25 and if it is blocked by your ISP or by your network firewall you may not be able to send emails using outlook. Please contact your network administrator or ISP to unblock port 25

Also you can use port 8090 as an smtp port, for this go to email settings > advanced tab > change smtp port to 8090

If its still not working please contact us at support@hosting.co.in