Setting up cold outreach mailboxes is a core part of managing your domains in Icemail. Whether you're adding a few mailboxes or uploading them in bulk for scale, this guide will walk you through both single and bulk creation workflows.
Make sure:
You have already connected your domain(s) to Icemail.
You know which mailbox type you need — use the [Icemail Mailbox Calculator](https://icemail.ai/cold-email-mailbox-calculator) to estimate how many mailboxes and domains you'll need based on your sending goals.
- Google Workspace — Licensed Google Business Starter (Icemail is an official Google Partner). US IP mailboxes. $2.50/mailbox/month. Recommended: 2–3 mailboxes per domain. - Microsoft 365 — Microsoft 365 Business Starter plan. US IP mailboxes. $2.50/mailbox/month. Recommended: 2–3 mailboxes per domain. - SMTP — Dedicated IP per domain. Up to 10 mailboxes per domain. 50 emails/day/mailbox. - Azure — 100 mailboxes per domain. $30/domain/month. Up to 10 emails/day/mailbox (5 cold + 5 warm).
Follow these steps to create and assign a single mailbox:
Log in to your Icemail account
From the left-hand menu, click on “Mailboxes.”
This button allows you to manually create and link a mailbox to a domain.
Enter the following:
- Email address (e.g., [email protected]) - Domain to associate the mailbox with - Password (if you’re creating mailboxes directly through Icemail) - Optional Tags for grouping (e.g., SDR1, Campaign A)
Note: Ensure all fields are accurate. Typos can cause login issues and domain conflicts.
>
The mailbox will be created and linked to your selected domain.
For scaling your campaigns, bulk mailbox creation is the most efficient option.
In the Mailboxes section, you’ll find the Bulk Upload option. Click it to begin.
Click “Download Sample CSV” to understand the exact structure required.
The sample file includes fields like:
- Email - Domain - Password - Tag (optional)
Fill in your mailbox data following the format exactly.
Double-check for typos and make sure all domains listed are already connected in Icemail.
Once your file is ready, upload it and hit “Assign Mailboxes.”
Icemail will automatically generate and assign all listed mailboxes to their respective domains.
Mailboxes will now appear in your dashboard, ready to be used for warmup or cold outreach.
Use tags to organize mailboxes by campaign, SDR, or region.
Enable auto warmup after mailbox creation to improve deliverability.
If you're using third-party services (like Google or Microsoft), complete manual login after mailbox setup for proper verification.
For best deliverability, follow these guidelines per mailbox per day:
| Mailbox Type | Cold Emails/Day | Warmup Emails/Day | Ratio | | --- | --- | --- | --- | | Google Workspace | 15 | 15 | 1:1 | | Microsoft 365 | 15 | 15 | 1:1 | | SMTP | 15 | 15 | 1:1 | | Azure | 5 | 5 | 1:1 |
Parallel warmup is always recommended alongside outreach. Run warmup and cold outreach simultaneously in equal portions.
Need assistance with mailbox setup or CSV formatting? Reach out to our team — we’re here to help.
Email: **[email protected]** Your data is always safe and encrypted.
