Yep.

I've already run into a few. I mentally thank them for preventing me from wasting my time and money with them.

Same. That said, sometimes it’s a config error. I sent a very annoyed email to a website that didn’t work on Firefox, only for them to tell me that it was a bug and that they fixed it.

Yep what a wild thing, to try and filter email domains so they can try and find "fake" providers

And since people won't use the website, the website won't use the list. So the list would be useless.
The maintainer seems to have followed the same interpretation, weighing legitimate use against spam use. This is the official response to the issue as of 8h ago:

Dear Contributors,

We value your suggestions for expanding our list of disposable email providers. Your input is crucial in enhancing our tool's capabilities.

Decision on Gmail and ProtonMail Inclusion

After thorough evaluation, we have resolved not to include Gmail and ProtonMail in our list. Our rationale is based on the following technical and operational considerations:

1. **Reputation and Reliability**
   
   * **Gmail and ProtonMail**: Established, reputable providers with a high trust level for personal and professional communication.
   * **Distinction**: Unlike typical disposable email services, they offer long-term, reliable email solutions.

2. **Active Abuse and Spam Prevention Mechanisms**
   
   * **Effective Systems**: Both providers have robust mechanisms to detect and mitigate abuse and spam.
   * **Proactive Monitoring**: Ensures a secure email environment, reducing the prevalence of malicious activities.

3. **Commercial Intent of Typical Disposable Email Providers**
   
   * **Focus**: Targeting providers driven by ad revenue, facilitating spam/abuse.
   * **Gmail and ProtonMail's Model**: User-centric, not primarily ad-driven.

4. **Domain Limitations**
   
   * **Effectiveness**: Limited domain offerings by Gmail and ProtonMail make them less susceptible to misuse.
   * **Strategy**: Focusing on providers with extensive, rotating domain lists for more impactful filtering.

5. **Individual User Accountability**
   
   * **Accountability Measures**: Both services have mechanisms to penalize users violating terms, decreasing misuse risks.

Summary and Next Steps

Including Gmail and ProtonMail does not align with our criteria for identifying disposable email services. Our aim is to target services significantly contributing to online spam and abuse, without impacting legitimate email services. We have reviewed your list and agree on adding some providers, like internxt.com (Reference). We will also incorporate the obvious choices from the tail of your list. We apologize for the delay in addressing this issue but intend to promptly resolve it by focusing on the most impactful additions.

Simple as, if they don't even support e-mail it's surely a rather shite site.

The closed garden corpo-approved electronic message service the github issue is talking about simply won't do.