Auto messages are NOT supported in automatic non-API.
They are only available when you work with our API option because we need to connect to your eBay account with the API to send messages through your eBay messages box.
However, you can use a dedicated auto-messaging app. It will appear in your eBay third-party authorizations. Since eBay recognizes that such an app is not a monitor, it should not potentially affect marking your account as a dropshipper account. So, it should be completely fine to use.
For example, there's this one:
Please note that most of the needs to send notifications to buyers already have an automatic solution inside eBay:
1. Tracking number - when it is updated in the order, eBay sends an email to your buyer notifying that his item is on the way.
2. Feedback reminder - if there is no feedback left by the buyer after 30 days, eBay will send him a reminder to do it.
3. Automatic feedback - can left by you to your buyer directly on eBay. Click here to see how.
🔔 Keep in mind that some buyers may not appreciate receiving too many automatic messages and might consider it spam. Therefore, all you might need, in addition to eBay's system messages, is perhaps only a "thank you for your purchase!" message immediately after the purchase to let the buyer know that you are there for them.