Unbox.imCan one mailbox bind multiple domains?
One person can own mail across multiple domains, but “one mailbox address” and “one account that manages many domains” are different. Unbox is built for the second case: one account, many domains, clear From addresses.
Short answer
You cannot magically make you@brand-a.com and you@brand-b.com the same SMTP mailbox while keeping correct authentication for both. What works well is one Unbox account with a mailbox (or alias) on each domain, plus shared queues for team addresses.
That gives you one login and one inbox view, while each send still uses the domain that matches the brand.
Aliases vs mailboxes vs shared queues
- Mailbox: a primary address someone signs into and owns (for example you@brand.com).
- Alias: extra local parts that deliver into an existing mailbox on the same domain.
- Shared queue: support@ or sales@ that several teammates can claim without sharing one password.
Practical setup for a solo founder
Add each domain, create your personal mailbox on each, and add support@ as a shared queue where customers write to the brand. Work from one Unbox inbox; switch From when you reply.
Common questions
- Can I forward everything to Gmail instead?
- Forwarding can collect inbound mail, but replies often break domain authentication. If customers must see your domain in From, host send on that domain too.
Related guides
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