Seeking Recommendations for Better Direct Mailer Providers

Anyone connecting direct mailer providers with Clay that they like? I've been using Click2Mail, but their API sucks. I'm having to webhook from Clay to n8n, then do the work in n8n and realizing I should just find another direct mailer provider with better webhooks, API setup, etc. so I can do it all in Clay. I'm looking into Lob and Postalytics at the moment.