You are exactly right: you are being punished for the actions of others.
To understand who those “others” are, we need to look at how email makes it off of your computer to its destination.
We think of email as being point-to-point, but that’s actually not the case at all.
Your email travels first to the server provided by your email provider. From there it’s forwarded on to the recipient’s email service provider, and then finally downloaded to your recipient’s PC or email program. In reality there could be many servers in between, but most email these days is delivered directly server-to-server.
If you or your recipient is using a web interface, like Gmail or Outlook.com, then your actions take place on the mail service’s server, not your PC. Your PC’s web browser simply acts as an interface to the mail server; it’s not your PC that sends the mail.
Regardless of how you use email, it’s the mail server’s role that provides the clue.
Most mail servers will pay attention to spam. In particular they will note how much they’re getting and from whom.
So, where does the recipient’s mail server get email? From your service’s server. It doesn’t come directly from your PC at your IP address; it comes from your mail service’s server at its IP address.
And that’s who gets blocked.
The IP address you’re seeing is that of your email service provider. You haven’t been blocked, they have.
And as a result, everyone else who uses that same email service is blocked here as well.
Who’s at fault?
So the question, of course, is who caused this to happen?
It (probably) wasn’t you – I believe you when you say you don’t send spam. Most people don’t.
No, it was probably some other customer of this email service provider. That customer sent email, as you do, through the email service provider’s server. The difference is, they sent a lot of it to the same server used by your recipient, and too much of it was marked as or just looked like spam. As a result, the recipient’s server blocked your email service’s server.
There are actually several ways this can happen:
- A real live spammer has an account with your email service provider.
- One or more customers of the email service provider have been infected with malware – and so their machines have become part of a spam-sending botnet.
- The email service hasn’t properly configured and secured their server and is running what’s called an “open relay” – a server through which anyone can send email. Including spammers.
Ultimately most email service providers are on the watch for all of these things. If the spammer has an account, they’ll soon find their account has been suspended. If infected customers are sending spam, they may also find their accounts suspended, or at least receive a warning that they must act on. And of course every email service should properly configure their own servers.
What should you do?
Your options are limited, but there are two things you can and probably should do:
First, report this to your email service provider. They’re the ones who are blocked, and they need to take action to get un-blocked.
Second, if your email is important and/or time constrained, send it using a different email service. This is why it’s often handy to have a spare free email account from services like Gmail, Yahoo! or Outlook.com. Even if one of those is blocked (which can happen) in addition to your own email service, it’s rare that all of them would be.