Mailshake Email Verification

Mailshake offers some deliverability controls within its platform. A dedicated pre-import verification pass with BillionVerify applies a consistent, source-independent quality standard before any list enters the campaign — regardless of where the addresses came from. That matters for teams importing from multiple sources or using lists of varying age.

Before. Warmup improves the reputation of the sending infrastructure. It does not validate specific contact records or prevent bounces from invalid addresses. Sending through Mailshake with a bad list during warmup introduces exactly the kind of bounce signal that erases warmup progress.

Put them in a separate, lower-volume Mailshake campaign and watch delivery behavior before committing to the full segment. Catch-all domains accept all incoming mail, but that acceptance does not guarantee the address routes to a real, active inbox. Mixing catch-all records into the main campaign distorts your open and bounce rate data.

Re-verify them before import. Lists that have been sitting in a spreadsheet for more than 60 to 90 days carry meaningful staleness risk. Contacts change jobs, domains expire, and inboxes get decommissioned. A list that looked clean when exported may have drifted significantly by the time it enters Mailshake.

No. Verification removes bounces from permanently invalid addresses and reduces risk from disposable and risky records. Temporary rejections, server-side quota limits, and catch-all addresses that prove inactive after verification are outside what any verification service can prevent. The goal is to remove the predictable, controllable bounce risk before the campaign starts.