Firewall issues: Some firewalls are designed to square non-program associations – check with your system administrators.
Intermediary setup: If you're utilizing an intermediary server to cause demands, to guarantee that it's arranged effectively. Mailman will utilize the framework intermediary naturally – custom intermediary information can likewise be included if it's required for explicit solicitations or spaces. You can see more data about the intermediary server utilizing the Postman reassure.
SSL endorsement issues: If you're utilizing HTTPS associations, you can kill SSL confirmation under Postman settings. On the off chance that that doesn't resolve the issue, your server might be utilizing a customer side SSL association which you can arrange under Postman Settings. Check the Postman Console to guarantee that the right SSL authentication is being sent to the server.
Customer authentication issues: The server may require customer endorsements. You can resolve this by including a customer testament under Postman Settings.
Erroneous solicitation URLs: If your solicitation incorporates factors, ensure that they're characterized in your condition or globals. Uncertain solicitation factors can bring about invalid server addresses.
Off base convention: Make sure that you're not unintentionally utilizing 'https//' rather than 'http://' (or the other way around) in your URL.
Invalid Postman conduct: It's conceivable that Postman could be making invalid solicitations to your server. Check your server logs (if accessible) to affirm if so.
Extremely short breaks: If you arrange a short break in Postman, the solicitation may break before culmination. Have a go at expanding the break to stay away from this issue as well as set it to zero (0) for endlessness
Invalid reactions: if your server sends mistaken reaction encoding blunders or invalid headers, Postman won't have the option to decipher the reaction.
Also, obviously, on the off chance that you run into issues that you can't resolve, make certain to document an issue on our GitHub issue tracker.