SMTP relay service for email marketing

Do not respond unless you meet all criteria. We use Hatchbuck ([login to view URL]) as our Customer Relationship Management (CRM) and Email Service Provider (ESP). We use Google to host our domain. Because of this, Google sets our email limit to 500 emails per day. We need to be able to send 1,000's of emails per day and ensure they don't end up marked as SPAM. We want to manage our campaigns ourselves, so no campaign-management-as-a-service options. Therefore, we need a technical solution that will enable us to continue to use Hatchbuck but relay or proxy our current SMTP service provided by Google to another SMTP server to avoid Google's daily email limit.