Your email list isn't just a collection of email addresses. Related: Don't Sleep on Email Marketing — Here's Why It's Still Your Business's Most Powerful ToolWhat taints your email sender reputationEvery email sender has a reputation with inbox providers – services like Google, Yahoo or Outlook that make email communication possible. Here are some of the common mistakes they make:Buying or scraping listsNever cleaning or validating email addressesSkipping email warmup altogetherWhenever you send an email, you're building – or tarnishing – your reputation with email providers. To reap the benefits of email marketing, build and nurture your own email list. Email marketing isn't dead, but lazy email marketing definitely is.