Discourse not sending Emails

No, I did not get 10/10 perfect rating, but I got 8.2/10 almost perfect rating as you can see in the screenshot below.

However, this is not the problem. The problem is emails are not even reaching to the email provider platform as evident on its logs. This problem vanishes when I send the restart command to our server and returns again within a time span of 4-6 hours, so the only viable solution we have found is to restart our server 2-3 times in a day which is highly unfeasible for us.