A more thorough explanation:

If you are a lawyer with a client who is complaining about spam emails, the first thing to worry about is whether your client has standing to bring claims under the CAN-SPAM Act. To have standing, your client must demonstrate that they are an "internet access service" provider and have suffered specific harm from spamming activities. This can be difficult to prove, and the standards are very high.

• Your client is a small business that provides email services to its customers. They have been receiving a lot of spam emails, which has caused them to spend a lot of time and resources dealing with the issue. However, they may not have standing to bring a claim under the CAN-SPAM Act because they do not offer enough services beyond email to be considered an "internet access service" provider.
• Your client is an internet service provider that has been experiencing a lot of spam emails that are causing their servers to crash. They have evidence that the spam emails are coming from a specific source, and they have spent a lot of time and money trying to block the emails. They may have standing to bring a claim under the CAN-SPAM Act because they can demonstrate specific harm from the spamming activities.

The examples illustrate the difficulty in establishing standing under the CAN-SPAM Act. The first example shows that simply providing email services may not be enough to qualify as an "internet access service" provider. The second example shows that specific harm must be demonstrated, such as server crashes, and that evidence must be provided to show that the spam emails are coming from a specific source.

Other potential issues to consider include personal jurisdiction, consent to receiving emails, and the types of remedies to be pursued.