Process certain job through a proxy

I've been investigating how to process certain Jobs through a proxy. I just need to connect to a smtp mail server from a different ip than my app server.

The only solution it came to my mind is creating many vps in Digital Ocean and execute the job code there. But sounds like its not an optimal solution.

Is there any other budget solution for this particular problem that i'm missing? Can i buy any ip service and connect directly from my server when running that job?

Thanks