After sending a message with Soapbox Mailer, feedback from Amazon for each Campaign Member is stored in the Campaign Member's SES SendEmail Response field. Sometimes, this field might include a code saying that the "Email address is not verified". Here are a few reasons why that might happen and how to resolve these issues.
1) Sender's email address hasn't been validated
If the Sender's email address for your Soapbox Mailer campaign has not been validated in Amazon, then your email will be rejected by Amazon and not sent. To fix this, go to Amazon SES and add the Sender's email address as a verified email address (or alternatively verify an entire domain).
2) You're in Amazon's non-production mode, and the recipient's email address is not verified
Unless you've requested production access to Amazon SES, you must ensure that all recipients' email addresses are verified in Amazon SES. To fix this, go to Amazon SES add each recipient's email address as a verified email address (or alternatively verify an entire domain). Alternatively, you can request production mode access to Amazon SES.