In the pre-warmed purchase wizard, choose Create Custom Addresses, then enter a first and last name for each mailbox (each becomes first.last@domain). You need at least 3 and can have up to 10 per domain. Winnr removes the warmed sample mailboxes and creates new ones with your names. The new mailboxes benefit from the aged domain's reputation but have no warming history of their own. Billing is the same $3 per address per month.
When custom is worth it
- Real sender identities. Cold email works better when the sender matches a real person. Custom lets you use your team's names.
- Consistency across domains. If you already send as
sam.lee@company-a.com, custom lets you addsam.lee@company-b.com. - One mailbox per rep. Each SDR gets their own mailbox on each domain.
When keeping the warmed addresses is better
- You want the highest inbox rate on day one. Kept addresses were individually warmed. Custom mailboxes start from the domain's reputation only.
- The names don't matter. If a sending tool or AI SDR sets the display name, the address itself matters less.
- Speed. Kept addresses are ready within seconds and there's nothing to type.
How it works
- In the wizard's Setup step, choose Create Custom Addresses.
- In Configure, edit the first and last names (5 random names are filled in to start). Use Add for more, up to 10, or the bin icon to remove one, down to 3.
- Review and purchase. The first month is charged immediately at $3 per address.
- Winnr removes the warmed sample mailboxes from the domain and creates your new ones. They appear in Email Users, marked as pre-warmed, once they're ready.
What the domain's reputation covers
Domain-level reputation applies to every mailbox on the domain:
- The domain's age
- Its clean warming history
- Authentication (SPF, DKIM, DMARC) already set up and in use
- A clean blocklist record at sale
Mailbox-level reputation starts fresh for custom addresses. Send modest volumes of clean mail at first and it builds within days.
What's next
Frequently asked questions
Should I use custom addresses or keep the warmed ones?
Keep the warmed ones if you want the strongest start, since each of those mailboxes has its own warming history. Choose custom if the sender names matter to you, for example to match your team's real names or the pattern you use on other domains.
Are custom mailboxes individually warmed?
No. They are new mailboxes on a domain with established reputation, so they benefit from the domain's history but start with no history of their own. If you want them ramped up before heavy sending, turn warming on for them ($0.60/mailbox/month).
How many custom mailboxes can I create per domain?
Between 3 and 10.
What format do the addresses use?
The wizard builds each address from the first and last name you enter, as first.last@yourdomain. A Randomize button fills in realistic names if you don't have specific ones. Through the API you can pass any valid local part.
Can I mix, keeping 2 warmed addresses and adding 3 custom ones?
Not in the wizard. Each domain is either all kept addresses or all custom. After purchase you can add more mailboxes to any pre-warmed domain through the normal Add Email User flow, up to 10 per domain, at $3/month each.
How long do custom mailboxes take?
They are created in the background after payment and are usually ready within a few minutes.
What names should I pick?
Real-sounding personal names work best for cold email. Avoid role addresses like sales@ or info@.