Keeping your prospect list clean

A clean list is the single biggest thing you control in deliverability. Accurate, relevant addresses mean fewer bounces, fewer complaints and more replies, which in turn protects your sender reputation. Distro handles some checks automatically, but it cannot tell you whether an address really exists or whether a person is a good fit.

What Distro checks automatically

When you add or import contacts, Distro checks each address and shows the result in the Email check column of your email contacts (People → Email contacts, or All contacts if you only use email):

When you import a CSV, duplicate rows within the file are collapsed, and by default existing contacts are left as they are. See Import prospects with a CSV and How duplicate detection works.

When you launch a campaign, Distro leaves out contacts who are on your Unsubscribed list, have unsubscribed, have hard-bounced, are invalid, are archived, or are already in the campaign. The launch check shows how many were excluded, and warns you if some recipients are already active in another campaign.

While a campaign runs, Distro re-checks each recipient just before every email. Anyone who unsubscribed, hard-bounced or was blocked in the meantime is skipped.

What you should check yourself

1. Source. Use addresses you found or collected legitimately. Do not use purchased, rented or scraped lists; Distro's responsible-use policy asks you to confirm this.
2. Freshness. People change jobs often. The older a list, the more of it bounces.
3. Fit. Every person should match your ideal customer. Irrelevant emails cause complaints, not just silence.
4. Role addresses. Shared inboxes like info@ rarely reach a decision-maker and are more likely to complain. Remove Risky role addresses unless you have a good reason.
5. Personalization data. Check first names, company names and any custom fields you use in your emails. Missing values can produce awkward emails like "Hi ,".
6. Your own team and customers. Exclude colleagues, existing customers and partners who shouldn't receive a cold campaign. Block their domains if needed.

Keep it clean over time

• Act on bounces. Hard bounces are blocked for you. If an address keeps soft-bouncing, remove or block it. See Why emails bounce.
• Respect opt-outs. Never re-add someone who unsubscribed or asked not to be contacted. See The Do Not Contact (suppression) list.
• Retire non-responders. Someone who never replied to a full sequence probably shouldn't get another one soon.
• Use lists and tags to keep segments tidy, so the right people land in the right campaign. See Lists, tags and custom fields.
• Test new sources small. Send a small first batch from any new list and check Bounced before sending to the rest.