Email campaigns crashing the website

I have an email list of 30,000.

Whenever I send a campaign email, I get a surge of traffic which increases the load time for my webstie and basically crashes my website.

I thought CDN would solve this issue but it didn’t. Are there any specific products/services that Cloudflare offers that can solve a sudden spike in traffic? Most of my subscribers are in US and Canada.

That very much depends on how your website works and why it it slow.

If there are simply too many requests that overburden your server’s bandwidth/cpu/ram, you can achieve a lot by caching as many assets as possible.
If your site is using Wordpress, APO could help

If your database or payment system can’t keep up with all the orders you receive, caching isn’t going to help. In that case, something like a Waiting Room might be for you, ensuring that the site at least works for some people:

Alternatively, you could think about getting a second server and load balancing.

There is no simple “one size fits all” solution. You need to first identify where exactly the problem lies.