Bulk Mailbox Invites

Send setup links to many people at once. You pick the domain; each recipient picks their own mailbox name and password when they complete setup.

Need admin-controlled passwords? Use Bulk Mailbox Creation instead -- upload a CSV with email addresses and passwords to create mailboxes immediately.

Who this is for

• Account owners onboarding entire teams or departments.
• Agencies rolling out email to multiple clients simultaneously.
• Admins migrating users from another email provider.

What you get

• Fast onboarding: Invite up to 500 recipients per batch instead of one at a time.
• No passwords in transit: Each recipient creates their own password directly.
• Validation before sending: Review your list, fix errors, and confirm before any emails go out.
• Plan limit enforcement: The system checks available slots so you never exceed your plan.

Before you start

• The domain must be Active (DNS verified).
• Your plan must have available mailbox slots. Pending invites count toward your limit.
• Prepare your recipient list as email addresses (one per line or comma-separated), or in a .txt file (max 1MB).

Input formats

You can enter email addresses directly or upload a file. To pre-allocate dedicated storage for a recipient, append a size token after their email — , 5 GB, , 2048 MB, , 1.5 GB. Recipients without a size token use the shared pool (the default).

Text area input:

alice@company.com
bob@company.com, 5 GB
carol@company.com
support@company.com, 2048 MB

You can still put multiple emails on one line (legacy comma-separated format), as long as you do not mix them with a storage token on the same line:

alice@company.com, bob@company.com, carol@company.com

File upload:

• Supported format: .txt (plain text)
• Maximum file size: 1MB
• One email per line; optional , <size> suffix for dedicated storage

Step-by-step: Sending bulk invites

Step 1: Input

1. Navigate to Mailboxes in the left sidebar.
2. In the Create New Mailbox card, select Bulk invites.
3. Domain: Choose the domain all mailboxes will belong to.
4. Email addresses: Either:
   • Paste addresses into the text area (one per line or comma-separated), or
   • Click Upload file (or drag and drop) to upload a .txt file.
5. Click Validate to proceed to the preview.

Step 2: Preview

The preview screen shows a summary and your categorized addresses.

Summary cards:

Address categories:

Editing invalid emails:

1. Click the pencil icon next to the email address in the "Invalid email" section.
2. Edit the address in the inline editor.
3. Click Save — the entire list is automatically re-validated. If the corrected address is valid, it moves to "Ready to send."

You can also click Re-validate at the bottom to manually re-check the entire list.

Note: Emails are validated for both format and deliverability. An address with a non-existent domain (e.g., user@fake.xyz) will be marked as invalid even if the format is correct.

Removing addresses:

Click the X button next to any address to remove it from the batch.

Step 3: Send

When your list is ready:

1. Review the Ready to send count.
2. Click Send X invites (where X is the number of valid addresses).
3. Wait for the confirmation screen.

Step 4: Results

The results screen shows:

• Successfully sent: Number of invites dispatched.
• Status: Confirmation that all invites were sent.

Click Done to return to the Mailboxes page.

What happens next

Each recipient receives an email with a one-time setup link. When they click it, they:

1. Choose their mailbox name (the part before the @).
2. Set their own password (minimum 12 characters).
3. Receive a recovery code for future password resets.

Once complete, the mailbox appears in your Mailboxes list as active.

Limits

Plan mailbox limits:

Pending invites count toward your limit. If you have 95 mailboxes on a Starter plan (100 limit), you can only send 5 more invites.

Quick fixes / Troubleshooting

Best practices

• Double-check your list before clicking Validate. It's easier to fix a text file than to cancel dozens of invites.
• Don't send to unverified addresses. Make sure recipients are expecting the invite to avoid spam complaints.
• Start small if you're unsure. Send a test batch of 5-10 invites before doing a full rollout.
• Monitor completion rates. Check your Mailboxes page to see which invites are still pending.