The CAN-SPAM Act directly affects email list building options, with the following rules and limitations:

1. Email addresses for mailing lists cannot be harvested from websites.

2. The person or company running the email marketing campaign is legally liable if they hire a contractor who harvests email addresses on their behalf, even if they don't personally participate in list building efforts.

3. Members of an email marketing list must have the option to opt-out of future mailings, or essentially remove themselves from the email marketing list.

4. Email marketers can't simply say ?I didn't know,? if they purchase or rent a cheap email list, or join ?safe lists,? that later prove to be a list of non-opt-in subscribers. Email marketers have the responsibility to know who they're buying from, and understand standard rates of legal email lists to avoid ?too good to be true? deals that are often illegal email collections.

Despite limitations on email list building under the CAN-SPAM Act, there are still ways to build an effective email marketing list, such as:

1. Opt-in subscription forms on a website.

2. Offline opt-in email subscriptions (such as through response cards in customer direct mail campaigns).

3. Including an opt-in email list subscription with a company's ordering process, to save the customer time and increase the likelihood of an opt-in subscription.

4. Offering incentives such as free e-books, software, etc. to convince subscribers to sign up for an email marketing list.

In the end, while the CAN-SPAM Act puts more limitations on email marketers and their list building abilities, the result is better quality mailing lists with targeted subscribers having a genuine interest in a company's message, products, or services, which increases potential conversions.