Sparkpost doesn’t send buddypress mails

Hi there,

I’m facing an issue for several hours now and i can’t fix it.
I’m using the sparkpost API method to send emails from my wordpress installation.

I can send the test email from sparkpost.
I set up a temporary contact form and i’m also able to receive emails from that form.

But i don’t receive all the buddypress mailing.
For example, when i send a message from one user to another, the receiver of the message should receive an email which tells him that he received a message on his account(in wordpress/buddypress).

These kind of emails aren’t being send over sparkpost.
Does anybody know the solution for this?
Is buddypress using another kind of email technique or something?

Thanks in advance,

Peter van Leeuwen