Unlike SMTP providers, a Zapmail mailbox is a real Google Workspace or Microsoft 365 account, and so is a PureMail inbox. Both send through Google’s or Microsoft’s own servers and start with the reputation those providers give their customers.
What differs is who builds it. On Zapmail you create the mailboxes in a dashboard and export them to your sequencer yourself. On PureMail our team does the whole job, including connecting each inbox to your sequencer, in about four hours.
So Zapmail vs PureMail comes down to two things: PureMail costs less month to month, and you hand the setup over instead of doing it yourself.