A best practice to keep deliverability high and bounce rate low is to routinely clear out all users that have bounced several times.
Iterable automatically unsubscribes users that hard bounce from whatever channel an email was sent from--sometimes, these hard bounce emails still cause future bounces (if there's more than one marketing channel, or if the hard bounce wasn't detected in our system and was a soft bounce).
Thus, users who soft bounce several times are probably not going to open future emails. This negatively impacts deliverability. Thus, we recommend going through a process of clearing these users out at least quarterly.
The overall process is to create a dynamic list that captures these users. Steps are below:
Create the dynamic list with a segmentation like the one below. You can choose however many bounces you'd like--the higher the number, the more conservative the clearing out will be. The list will be smaller if the number of bounces is higher.
1. After you create this list, download the list when you want to wipe out the users-->go to Users>List
2. Select the dynamic list you made.
3. Click refresh & export to csv
4. Go back to Users > List and click "Channel Unsubscribe Users"
5. Upload the csv you just downloaded, select which channels you'd like to unsubscribe them from, and click "Remove Subscribers." We recommend unsubscribing users from all marketing channels, but keeping transactional channels open if the user makes a purchase or does an action that prompts a transactional email.
Repeat this process periodically to help maintain an optimal deliverability and keep a low bounce rate.