Azure B2C support for Exchange on-prem as custom email provider?

Dear Microsoft-community,

Our customer in healthcare is implementing Azure B2C to offer CIAM for their clients and relatives including personal caretakers. 

Aside production services, we have a development/test environment including an on-premises Exchange Server to check if e.g. user imports are working and new custom policies. However, no emails are allowed to be sent from this dev/test environment to those actual personal email addresses.

So our question: does Azure B2C support using this on-premises Exchange Server as custom email provider?

I suppose it should, since 3rd party HTTP-based email providers like SMTPGrid and MailJet are supported by Azure B2C. However, I cannot find a single online post if the Exchange Web Services will work similarly? (e.g. https://webmail.companyname.tld/EWS/Exchange.asmx )