Why Are My Gmail Emails Bouncing Back with a 450-4.2.1 Error?

It sounds like you're experiencing an issue where every email in your Gmail account is generating a fake email. This can be quite frustrating, but there are a few things we can check to troubleshoot the problem. First, it's important to determine when this issue started. Since you mentioned it began a few months ago, we should consider any changes that might have occurred around that time, even if you believe there haven't been any. Sometimes, updates or new apps can inadvertently affect how your email functions. You’re accessing your email from both a PC and an iPhone, which is useful to know. When we troubleshoot, we’ll want to look at the settings on your PC, as that’s where we can often find the root of the issue. It would be best to connect when you’re in front of your computer so we can go through the settings together. If you’re available tomorrow morning at 12 PM EST, I can give you a call then. We can take a closer look at your email settings and see if there’s anything unusual, such as filters or forwarding settings that might be causing these fake emails to appear. In the meantime, if you can, check if there are any suspicious apps or extensions linked to your Gmail account that you don’t recognize. Sometimes, third-party applications can create issues like this. Let’s touch base tomorrow, and I’m confident we can get to the bottom of this together.