At marketplace purchase, tick "Custom email addresses" and enter the local parts you want (sam, alex, jordan, etc.). Winnr drops the sample mailboxes and provisions brand-new mailboxes on the aged domain with your local parts. Domain reputation is inherited; individual mailboxes are new so they aren't individually warmed, but they still send well because of the domain's reputation.
When custom is worth it
- Personal brand. Cold email works better when the sender name matches a real person on your team. Custom lets you use their real first names.
- Consistency across domains. If you already have
sam@company-a.comand wantsam@company-b.com, custom aligns them. - Team member match. Each SDR gets their own dedicated mailbox on each domain.
When samples are fine
- You just need mailboxes. If you're feeding them into an AI SDR that generates the sender identity dynamically, the underlying local parts don't matter much.
- You want the highest possible inbox rate on day one. Samples were individually warmed to a high health score. Custom mailboxes start at domain reputation (still high) but without individual warming history.
- Speed. Samples are faster to set up (nothing to type).
What the domain's reputation covers
Domain-level reputation carries across all mailboxes:
- Age of the domain (established sender signal)
- Clean warming history at the domain level
- SPF/DKIM/DMARC setup already trusted by providers
- Blocklist status (clean domain lifts new mailboxes)
Mailbox-level reputation is per-mailbox and starts fresh for custom addresses. Send clean content and you'll get individual mailbox reputation up to par within days.
What's next
Frequently asked questions
Should I use custom usernames or take the samples?
If you have a brand voice — first names of your SDRs, matching your other domains' patterns — custom is better. If you just need mailboxes to send from and don't care about local parts, samples are one less thing to configure.
Are custom mailboxes individually warmed?
No — they're freshly provisioned. But they live on a domain with strong warming history, so they inherit the domain-level reputation. In practice that means their day-one deliverability is high, carried by the domain's established reputation even without individual warming.
How many custom mailboxes can I choose per domain?
Up to the standard cap (10 mailboxes per domain).
Can I mix — keep 2 samples and add 3 custom?
Not at purchase. You get all samples or all custom for the domain. But you can create additional custom mailboxes on any pre-warmed domain later via the standard Add Email User flow (up to the 10-mailbox cap).
What names should I pick?
First names match SDR identities well (sam, alex, jordan). Skip generic labels like sales@ or info@ — they hurt deliverability.