My email client stopped syncing new emails. I can see old emails but new ones aren't appearing even though I can see them on the web.

Use asynchronous programming patterns with explicit controls on the number of concurrent tasks.

Configure your application to limit the number of active connections to the API at any given time.

Queue failed requests and process them with appropriate delays to avoid overwhelming the API.

When a rate limit is hit, wait for an increasing amount of time before retrying the request.

Check if the API offers endpoints for retrieving or manipulating multiple resources at once.

If the API supports it, group multiple data fetches or updates into single requests.

Contact the API provider to inquire about increasing your rate limit if your usage is legitimate.

Review your application's logic to reduce unnecessary or redundant API calls.

Add logic to your application to control the rate at which it sends requests to the API.

Start your computer with a minimal set of startup programs and services to identify if any background software is causing the conflict.