Email spam received at multiple email addresses?

As a counter measure against spam I always use an unique email address for everything. These unique addresses get forwarded to my real email address setup in cpanel.

For example, my real email address might be me@mydomain.com; then they are forwarded addresses like 1.me@mydomain.com, 2.me@mydomain.com, 3.me@mydomain.com, etc.

Each forwarded email address only gets used once for a specific purpose. If I receive spam from a particular address then I’ll know you it was from and can disable that email forwarder without affecting the others.

My problem is I am receiving spam daily on separate email forwarders.

Although most of these emails are used to sign up for emailing list, I am doubtful that several separate email list owners have independently decided to spam me.

Could this be a brute force attack or a problem with my email server?