How to Create a New Mailbox in TrekMail (4 Methods)

A mailbox is your identity on the internet (like sales@yourcompany.com). You can create as many mailboxes as your plan allows.

Who this is for

• Admins setting up their team.
• Users adding a new alias like support or hello.
• Account owners inviting users to set up their own mailbox.

Before you start

• Domain status: You can prepare a mailbox while its domain is still waiting for DNS. Do not depend on that mailbox for normal mail delivery until the domain shows Active.
• A domain we host the mail for: a domain whose incoming mail stays with another provider cannot hold mailboxes, so it is not offered in any of the pickers and an invite on it is refused. See Send From a Domain You Do Not Host.
• Plan Limits: Check your plan usage on the Overview page. Nano plans have a limit of 10 mailboxes per domain; paid plans vary (Starter: 100, Pro: 300, Agency: 1,000). New and trial accounts can have a lower temporary creation cap; the form shows the limit currently enforced for the account.

Choosing a creation method

There are four ways to create a mailbox:

• Invite owner: Send a setup link to one person. They choose their own email address and password. Best for onboarding individual team members.
• Bulk invites: Send setup links to many people at once (up to 500 per batch). Recipients each choose their own address and password. Best for onboarding entire teams or departments quickly.
• Create manually: You set the address and password yourself. Best for shared mailboxes or when you control all credentials.
• Bulk create: Upload a CSV or paste data to create many mailboxes at once with admin-set passwords (up to 500 per batch). Best for provisioning many accounts across multiple domains in one go.

Tip: Not sure which to pick? Use the "Guide" button on the Mailboxes Page to take an interactive tour that demonstrates all four methods using simulated data.

Option A: Invite owner

Let users set up their own mailbox. You pick the domain; they pick the local part (e.g., alice) and password.

1. Navigate to Mailboxes in the left sidebar.
2. In the Create New Mailbox card, select Invite owner.
3. Domain: Choose the domain the mailbox will belong to.
4. Recipient email: Enter the email address where the setup link will be sent.
5. Storage (optional): by default the new mailbox uses Shared Storage from your account pool. To carve out a fixed amount, untick Shared Storage and enter the size in MB or GB. The owner inherits this allocation when they redeem the invite.
6. Click Send invite.

The recipient receives an email with a one-time setup link. When they complete setup:

• They choose their local part (e.g., alice@yourdomain.com).
• They set their own password (minimum 12 characters).
• They receive a one-time recovery code for the mailbox handoff. It expires after 24 hours, so it should not be treated as a permanent backup credential.
• The mailbox appears in your list as active, with the storage choice you preselected.

Tip: You can resend, edit the recipient, or cancel pending invites from the Mailboxes page. Pending dedicated invites already count against the available pool, so you cannot accidentally over-commit.

Option B: Bulk invites

Send setup links to many people at once. You pick the domain; each recipient picks their own local part and password.

1. Navigate to Mailboxes in the left sidebar.

2. In the Create New Mailbox card, select Bulk invites.

3. Default domain: Choose the domain most recipients will use. You can override it for an individual line in the detailed bulk-invite format.

4. Email addresses: Enter recipient email addresses in the text area (one per line), or upload a text file in the same format. To pre-allocate dedicated storage for a specific recipient, append , 5 GB (or , 2048 MB) right after the email, leave the size off to use the shared pool. Mix and match freely:

   john@example.com
   jane@example.com, 5 GB
   support@company.org, 2048 MB
   bob@example.com
   

5. Click Validate to review your list.

The preview step shows:

• Current mailboxes – existing mailboxes on the domain
• Pending invites – invites already sent but not yet completed
• Plan limit – maximum mailboxes allowed for this domain
• Available slots – how many more invites you can send

Your addresses are sorted into categories:

After fixing any issues, click Re-validate to refresh the list. When ready, click Send X invites.

Each recipient receives an email with a one-time setup link. When they complete setup, their mailbox appears in your list as active.

Tip: For detailed guidance, see Bulk Mailbox Invites.

Option C: Create manually

Set the address and password yourself.

1. Navigate to Mailboxes in the left sidebar.
2. In the Create New Mailbox card, select Create manually.
3. Domain: Select the domain this mailbox belongs to.
4. Mailbox Name: Enter the part before the @.
   • Tip: Use standard names like contact, info, or first names.
5. Password: Enter a strong password or click 🔑 Generate Strong Password.
   • Important: This password is for the mailbox (IMAP/SMTP/Webmail), not your TrekMail account.
6. Storage (optional): leave Shared Storage ticked (the default) to draw from the account pool, or untick it to carve out a fixed amount in MB or GB. A live "Available" indicator shows how much is left.
7. Click Create Mailbox.

Note: We only show the password once for security. Copy it immediately to your password manager.

Edit later: You can switch a mailbox between shared and dedicated at any time from the 3-dots menu next to it → Edit storage.

Option D: Bulk create

Upload a CSV file or paste tabular data to create many mailboxes at once. You provide full email addresses and passwords; mailboxes are created immediately.

1. Navigate to Mailboxes in the left sidebar.
2. In the Create New Mailbox card, select Bulk create.
3. Paste your data into the text area (one account per line), or drag and drop a .csv file. The browser accepts files up to 10 MB, and the submitted text must be no more than 500,000 characters, so a dense file can reach the text limit first.
4. Click Validate to review your data.

CSV format

The first row can be a header row (auto-detected) or data. Supports both comma-separated and tab-separated formats (paste from Excel/Google Sheets). Examples:

email,password
john@example.com,SecurePass123!
jane@example.com,AnotherPass456,5 GB
support@company.org,P@sswOrd!2026,2048 MB

Preview step

A domain limits table shows available slots per domain. All rows appear in a single list, issues first, ready last. You can Generate or Edit passwords for weak entries, and Remove any row. Removing a Ready row automatically promotes an Over Limit row from the same domain.

For full details, see Bulk Mailbox Creation.

After creation

• Download credentials: Click Download CSV to save a file with all created email addresses and passwords. Share this securely with mailbox owners.
• DNS warnings: A mailbox can be created before DNS verification finishes, but email will not flow normally until DNS is set up and the domain is active.
• Failed rows are listed with reasons so you can fix and retry.

Note: Passwords are shown once in the download. Save the file immediately.

Common mistakes

• Symptom: "Domain not found" in dropdown.
• Cause: The domain may still be "Pending DNS" or may be configured to keep incoming mail with another provider.
  • Fix: A pending domain can still be prepared for mailboxes; finish DNS before relying on delivery. A sending-only domain cannot host mailboxes, so use a domain TrekMail hosts instead.
• Symptom: A domain you definitely own is not in the dropdown, and a line under it says domains hosted elsewhere are not listed.
  • Cause: That domain keeps its incoming mail with another provider, so there is nowhere here for mail to be delivered and it cannot hold mailboxes.
  • Fix: Use a domain we host the mail for, or add a sending address on that one instead, see Send From a Domain You Do Not Host.
• Symptom: "Plan limit reached".
  • Fix: Upgrade your plan to add more users, or delete old unused mailboxes.
• Symptom: "Link expired" when recipient clicks invite.
• Cause: Invite links expire after seven days.
  • Fix: Go to Mailboxes, find the pending invite, and click Resend.
• Symptom: Recipient didn't receive the invite email.
  • Cause: Email may be in spam, or the address was incorrect.
  • Fix: Check their spam folder, or edit the recipient email and resend.

What's next

After creating a mailbox, you can add aliases: extra addresses that deliver into the same inbox. For example, add info@company.com and sales@company.com to a single mailbox. See Email Aliases Overview.