We email when we fulfill the order to let them know its been processed, a thank you, and when to actually expect if the source provided actual eta which includes xxx for the handling/shipping out time. Since many sources dont ship for up to 3 days this email in between seems to help show the customer we are looking out. You can potentially use selling manager pro (free with mid level store or 15.99) to just customize the standard ebay thank you when you purchase message and not send anything else but whether you or va do it, its not really a big deal to just send a msg manually after you order it.
I personally send a message automated at time of delivery using the app AFTERSHIP to let them know its arrived, to notify me in case of issues and then to leave feedback when 100% satisfied, so that if they price shop later we dont have to necessarily refund all the way since they already left feedback. We also send one only upon out for delivery and delivery issues To me its worth the fees, likely not really for someone just starting out, but once you are doing this regular it may really help. I have never had a negative feedback as most were prevented by this and we just take care of their concerns. No question there were many that would have become neg feedback had I not done this.
You can also try feedback-reminder.com to just send a canned message a certain # of days after ship such as just to leave feedback, or remind if any issues to contact you etc, this is far cheaper at 3.99/mo for when your starting out. You could just use aftership without emails for free to check status of all packages and manually send a msg too or keep some list with tracking #'s for awhile while small and check them then msg. Many ways to do it, or when starting send nothing at all. Ebay contacts them 30 days later to leave feedback, which they probably forget if its bad or not. The issue is of course that you dont then have any contact when there are issues, which leads to more possible negative then positive experiences.