We are trying to set up MS Dynamics-Marketo integration. What happens if an account is deleted in MSD, is the record also deleted in Marketo?
While this is the Salesforce documentation, it's logical to think Dynamics works in the same way... https://docs.marketo.com/pages/releaseview.action?pageId=7515131
Do you have a "Dynamics is Deleted" or simply "is Deleted" field in Marketo? If people are deleted in Dynamics likely that flag switches to true. They aren't automatically deleted in that case, but you can run automated flows to delete them in Marketo too if you like.
When Marketo and DCRM are integrated together, a new field will be added called Microsoft is Deleted. This field value is changed to True when a lead/contact is deactivated or deleted in Microsoft Dynamics CRM.
You can also create a custom sync filter that will allow you to delete records in Marketo, while keeping them in DCRM. This can also be used if you want to sync only part of your DCRM database in Marketo. More information here: https://docs.marketo.com/display/public/DOCS/Create+a+Custom+Dynamics+Sync+Filter
I hope this answers your question.