This operation can be used to create a new split test campaign within your account. You are able to split test on subject, from name, from address and both HTML and plain text versions of the campaign.
The numbers of variations must be equal for all specified properties. For example, if you supply 3 subject line variations, but only 2 from name variations, the campaign will fail validation.
If you don't specify a reply action, then 'Unset' is the default setting that you'll see in the result.
If you're using a 'reply to address', then replies will get stored both in-app and will also go to the 'reply to address' specified. This is also true of the 'WebMailForward' and 'WebMail' settings and thus you will not need to set these.
If you don't want replies to be stored in-app, then set the reply action to 'Delete' (thus they will be deleted). If you're using a 'reply to address' then replies will still go there.