What happens with existing members when you add a new email to a sequential autoresponder series in Arigato PRO?

The answer is simple: the email will be sent only to the users who are registered exactly X days ago (and will of course be sent in the future to the other new or existing members when the right day for them comes). It’s important to know that emails will never be sent on wrong dates, i.e. if existing member is registered more than X days ago, they will not get this newly added email. Here is an example to make things easier to follow:

If you add “1 day after registration” email on Oct 29, on the same day it will be sent to existing members registered on Oct 28 (provided that your cron job runs after adding the email). On Oct 30 it will be sent to members registered on Oct 29 etc. Such email will never be sent to members registered on Oct 27 or any earlier date. This is very logical and it is the way it should be.

If you want to send email to older members, you can send them a newsletter.