[shimo5037]

You must not have been looking very hard. Searching for "email" on the policy page gives you:

> Responsibility for Your Site > > 5. You will not engage in any promotional, marketing, or other advertising activities on behalf of us or our affiliates, or in connection with the Amazon Site or the Associates Program, that are not expressly permitted under the Associates Operating Agreement. For example, you will not engage in any promotional, marketing, or other advertising activities in any offline manner, including by using any of our or our affiliates’ trademarks or logos (including any Amazon Mark), any Content, or any Special Link in connection with an offline promotion or in any other offline manner (e.g., in any printed material, mailing, SMS, MMS, email or attachment to email, or other document, or any oral solicitation).