Creating a New Mailbox
This guide explains Three ways to create mailboxes: single invite, bulk invites, or manual creation. so you can complete the TrekMail task with confidence.
Article details
Type, difficulty, plans, and last updated info.
▼
Article details
Type, difficulty, plans, and last updated info.
- Type
- Guide
- Difficulty
- Beginner
- Plans
- Starter · Pro · Agency
- Last updated
- Apr 29, 2026
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
supportorhello. - Account owners inviting users to set up their own mailbox.
Before you start
- Active Domain: You cannot create a mailbox until your domain status is Active (DNS verified).
- 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: 1000).
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.
- Navigate to Mailboxes in the left sidebar.
- In the Create New Mailbox card, select Invite owner.
- Domain: Choose the domain the mailbox will belong to.
- Recipient email: Enter the email address where the setup link will be sent.
- 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.
- 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 recovery code for future password resets.
- 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.
-
Navigate to Mailboxes in the left sidebar.
-
In the Create New Mailbox card, select Bulk invites.
-
Domain: Choose the domain all mailboxes will belong to.
-
Email addresses: Enter recipient email addresses in the text area (one per line), or click Upload file to upload a
.txtfile (max 1MB). 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 -
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:
| Category | What it means | What you can do |
|---|---|---|
| Ready to send | Valid and within plan limits | Remove if needed |
| Invalid email | Malformed email format | Edit inline or remove |
| Duplicate in batch | Same email appears more than once | Remove one copy |
| Already invited | A pending invite already exists | Remove or keep as duplicate |
| Over limit | Exceeds your plan's mailbox limit | Upgrade plan or remove |
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.
- Navigate to Mailboxes in the left sidebar.
- In the Create New Mailbox card, select Create manually.
- Domain: Select the domain this mailbox belongs to.
- Mailbox Name: Enter the part before the
@.- Tip: Use standard names like
contact,info, or first names.
- Tip: Use standard names like
- Password: Enter a strong password or click 🔑 Generate Strong Password.
- Important: This password is for the mailbox (IMAP/SMTP/Webmail), not your TrekMail account.
- 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.
- 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.
- Navigate to Mailboxes in the left sidebar.
- In the Create New Mailbox card, select Bulk create.
- Paste your data into the text area (one account per line), or drag and drop a
.csvfile (up to 10MB) into the upload area. - Click Validate to review your data.
CSV format
| Column | Required | Description |
|---|---|---|
| Yes | Full email address (e.g., john@example.com) |
|
| password | Yes | Min 12 chars, must include uppercase, lowercase, and number |
| storage | No | Dedicated allocation like 5 GB or 2048 MB. Empty = shared pool. |
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: If any domains aren't verified yet, a warning appears. Emails won't flow until DNS is set up.
- 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: Your domain might still be "Pending DNS".
- Fix: Go to Domains and verify your records first.
- 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 a set period.
- 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.
Related articles
Jump to nearby guides that continue the workflow.