Must use specific email provider for CRM
The first problem is, in order to use the CRM, the organization must be ready to commit to the specific email service provider. That means if the CRM offers integration with say Gmail then you must be ready to use Gmail as your email service provider. However once you put the CRM in use, you will lose the flexibility of changing the email service.
So what happens if your organization grows to sizeable number and you need to consider a new email strategy ?