Mailbox vs alias vs forwarding vs catch-all
These four words sound alike but do different jobs. Use this guide to decide what to create for addresses like hello@, support@, or billing@.
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The short version
Create a mailbox when someone needs a real inbox and replies from that address. Use an alias when another address should land in an existing mailbox. Use forwarding to copy mail somewhere else. Use catch-all when one mailbox should get mail sent to addresses you have not created yet.
Sending from an alias
Every alias you create shows in the From menu of the Shipmail web composer, for anyone with access to its mailbox. New messages, replies, drafts, and scheduled sends keep the alias you pick. A reply starts from the alias that received the original message, and you can pick another sender before you send.
The alias uses its mailbox's display name and signature. You cannot start a new email from a catch-all address, a plus-address variant, a forwarding destination, or an address you have not created. The one exception is a reply: when mail reached the mailbox through the catch-all, your reply goes out from the address it was sent to. Sending as an alias works in Shipmail webmail only, not in SMTP clients or the public sending API.
An alias can use any verified domain in your organization, with any free name before the @. So one mailbox can receive and send as hello@brand-one.com and hello@brand-two.com without a second inbox and without using another mailbox from your plan.
What each one means
Mailbox
Its own inbox, with a login.
you@yourdomain.com
Alias
Delivers into an existing mailbox.
sales@ → hello@
Forwarding
Relays to an external address.
press@ → you@gmail.com
Catch-all
Anything unassigned lands in one mailbox.
*@yourdomain.com → hello@
Mailbox
A real inbox with its own password, storage, sent mail, and IMAP/SMTP access.
Example: hello@yourdomain.com
Use when: Use a mailbox for an address someone reads and replies from every day, like hello@, support@, or billing@.
Alias
An extra address that delivers into an existing mailbox. You can send as it from Shipmail's web composer. It has no inbox or password of its own.
Example: hi@yourdomain.com delivers to hello@yourdomain.com
Use when: Use an alias when two public names should land in the same place, like hello@ and hi@ for the same founder inbox.
Forwarding
A rule that sends a copy of incoming mail to another address, usually outside Shipmail.
Example: billing@yourdomain.com forwards to jane@gmail.com
Use when: Use forwarding when someone only needs copies somewhere else. If they also need to send from the address, create a mailbox instead.
Catch-all
A fallback mailbox for addresses on your domain that you have not created yet.
Example: anything@yourdomain.com lands in hello@yourdomain.com
Use when: Turn on catch-all early so you do not miss typos or one-off addresses. Turn it off later if it brings in too much spam.
How to choose
Solo founder starting out
Create hello@ as a mailbox. Add support@ or billing@ as aliases if the same person handles them all.
Team with separate responsibilities
Create support@ and billing@ as mailboxes when different people handle them and each needs its own inbox.
Need to send mail to an outside address
Use forwarding for receive-only copies. If the person needs a separate inbox, password, or IMAP/SMTP access for billing@, create a mailbox instead.
Not sure which addresses people will use yet
Enable catch-all on hello@ so typos and made-up addresses do not bounce while you learn what customers use.
How forwarding works in Shipmail
You set up forwarding on a mailbox. It can cover the mailbox's main address or any of its aliases, so an alias does not need a mailbox of its own.
- Open Settings > Incoming mail > Forwarding.
- Add up to three outside destinations.
- Each destination gets a confirmation link from Shipmail. Forwarding starts once it is clicked.
Shipmail keeps the original in the mailbox and sends a copy to each confirmed destination. It filters spam first, so spam stays in Junk and is not forwarded.
To forward mail for one alias, use Forward this alias in the alias row menu, or pick it under Only mail sent to when you add the destination. It uses the mailbox's forwarding settings. Choose All mailbox addresses to match every address. You can also set an exact sender. When you set both, mail has to match both. Use an inbox rule when you need to move, flag, or send a webhook for the matching mail.
A simple starting setup
For most new domains, start with hello@ as a mailbox. If the same person answers customers and invoices, make support@ and billing@ aliases that deliver to hello@. When someone else starts handling support or billing, turn that address into its own mailbox.
If you are still testing names, enable catch-all on hello@ for a while. Turn it off once you know which addresses customers use.