If you can't find any emails migrated from Sugar, this might have happened because your emails are only implicitly referencing a contact (i.e. they don't have a direct relation to the contact).
If your new CRM doesn't have a feature like that, you will not see these emails imported.
We can build a custom script to mimic the Sugar functionality and attach emails to a contact if the email address matches. This would be a customization, so please reach out to us so we can review the details together.