The error with the code 429 (“Too Many Requests”) is not from the proxies. Comes from the site where you are using the proxies because you made too many requests in a short period of time
The 407 error ( Proxy authentication required ) appears in one of this situations: you are using some proxies which aren’t anymore on your list ( have expired, were replaced, you got a new list) you are sending a bad user/pass for the proxies (maybe some extra spaces after the user or pass?) or you aren’t […]
Usually, the 403 Error ( Forbidden ) means that the proxy got banned on that site, probably because too many requests were made in a short period of time. The ban might be temporary or not, depends on the site.
Usually the 503 Error ( Service Unavailable ) means that the proxy got banned on that site, probably because too many requests were made in a short period of time. The ban might be temporary or not, depends on the site.
The 406 error code appears if you use the same proxy from more than 2 computers in the same time. This error will disappear in max. 5 minutes after you stop using from more than 2 computers.
If you get HTTP code 429 (Too Many Requests) , it means that you are making too many requests to a certain site and that site is blocking you
Usually, 503 code is a ban on your destination site because you made too many requests