Third party email service and SPF

Question

I am using third party email service (mailing list, like Mailchimp or similar) and I have included ip-address of that server on SPF record in my domain name.

Same third party email service is used 10 other users and those users does not see each other.

What will happend if somebody else uses that same third party server and send spam with my address from it? Is that email rejected on target server or not? If not, can i somehow prevent that?

Answer 1

SPF cannot protect against this, but DKIM can - this is why you need to use both.