Hello
I am new to Marketing Cloud and need to delete contacts as we have exceeded our contact limits. I have read some Salesforce Articles and followed steps to create 2 data extensions with a list of customers to delete but was hoping someone could help validate the right steps were followed?
PROCESS ONE - followed steps in (AllContacts System Data View)
- This instructs me to first create a filtered DE from the Mobile List tab in All contacts and selecting Mobile list as the channel and then setting a filter: contact key is not null. What I am not sure about is, is this pulling only contacts in MobileConnect or all our contacts where the contact key is not blank? This filtered DE picks up 160,948 contacts which matches the number under the All contacts tab (160,948).
- I then ran the following SQL query as per the salesforce article: select subscriberkey from [Contact key is not null - All contacts] which returned 160,948 records which matches the All contacts list.
- To identify contacts from this DE that have not been sent an email OR SMS, I set up the automation with following SQL theory (not 100% sure if this is calling only customers who haven't received an email only or both email or SMS: SELECT c.SubscriberKey FROM [All Contacts View] c LEFT JOIN _Sent s ON c.SubscriberKey = s.SubscriberKey WHERE s.SubscriberKey IS NULL
- Which returned 129,358 records which I intend to delete. However, I wanted to confirm that the SQL queries used and the steps followed are correct and these 129,358 records are contacts that have not received an email or SMS from us via marketing cloud?
Process Two - followed steps in Salesforce article Permanently remove Contacts or Subscribers and associated data from Contact Builder
- This process was getting me to identify contacts without a channel which i understand are contacts we have not sent emails or SMSs to but also deletes contacts that were injected in a journey but did not get the email sent to them (which i am not sure if we should keep these customers or delete)
- When I followed these steps to create a filtered DE in Mobile lists, it picked up 125,891 contacts
- And then I use the sql query to create the data extension which pulls 125891 records which matches the above number.
I just wanted to see if anyone can help me validate the steps followed in these 2 options in deleting contacts are correct and if so, which is the better way to identify and delete contacts that have not received emails or SMSs from us or if I am completely wrong in my approach, that would be good to know too!
Thanks
Lukas Lunow (NoA Ignite) 
Forum Ambassador
So, going through your questions one by one:
What I am not sure about is, is this pulling only contacts in MobileConnect or all our contacts where the contact key is not blank?- a contact key will never be blank on a contact. But the list requires to have a selection criteria. Selecting "key not blank" will,. in other words, select all contacts.
To identify contacts from this DE that have not been sent an email OR SMS, I set up the automation with following SQL theory (not 100% sure if this is calling only customers who haven't received an email only or both email or SMS.
- the query is OK, but keep in mind it will also find contacts who might just have entered 3 hours ago, and are yet to receive an email. These contacts can still be valid. So you will need to check that they are not "recent". Also, _sent data view only holds data 6 months back, so a contact COULD have been emailed more than 6 months ago, but will not appear in the data view. And SMS are not part of _sent data view.
You are more or less correct on your approach, but I will also include criteria to delete subscribers who have been emailed recently, but are in Held (undeliverable) status in All Subscribers. There are more aspects which you might consider if you want to narrow or broaden your criteria.
