Does SES verify delivery to S3 before before calling next action?

Hi,

I have a rule that forwards incoming mail to 2 different S3 buckets using a rule which consists of an action for each S3 bucket, meaning that action 1 deposits the data in bucket 1 and action 2 of the rule deposits the email in bucket 2.

Can I assume that SES will only continue to action 2 once action 1 has successfully been completed? Meaning, can I trigger a lambda function through the delivery in bucket 2 that assumes a successful delivery to bucket 1? Or should I use a waiter in the lambda function?