Export Mailboxes to Icemail and Launch Campaigns in 30 Minutes

Export Mailboxes to Icemail and Launch Campaigns in 30 Minutes

You can move Google Workspace or Microsoft 365 mailboxes into Icemail, check DNS, configure authentication records, and start sending in about 30 minutes - if your CSV files, mailbox access, and DNS login are ready first.

If I had to sum up the process in a few lines, it would be this:

• Export your mailbox list from Google Workspace or Microsoft 365
• Reformat that file so Icemail can map each sender
• Connect inboxes with OAuth or SMTP/IMAP
• Check SPF, DKIM, and DMARC
• Keep new inboxes at 5 emails per day at first, then add 5 per day over about 3 weeks
• Stay under 30 to 50 emails per inbox per day
• Use 3 to 4 mailboxes per domain, and do not go past 5
• Import your lead CSV, map fields, and send a short first sequence

There are also a few failure points worth watching right away:

• A bad Microsoft 365 login can trigger a 5.7.57 error
• More than one SPF record on a domain can hurt delivery
• New inboxes sent at full volume too early are more likely to get filtered
• Dirty lead lists can push bounce rates above 2%, and 5%+ is a danger zone

One point that stands out: Icemail is positioned as the faster option over manual setup, with pricing at $2.50 per mailbox per month, free mailbox replacements, and U.S.-based IPs for teams sending into the U.S.

So if you already have mailboxes and a cleaned CSV, I'd treat this as a simple four-part job: export, connect, verify, send.

The Cold Email Deliverability Playbook: Setup, Warm-Up & Scaling Right

Export your mailbox list from Google Workspace or Microsoft 365

Icemail only needs the mailbox details required to match each sender: email address, display name, domain, and connection settings.

Export Google Workspace users to CSV

In Google Admin Console, go to Directory > Users and export the user list as a CSV file.

Export Microsoft 365 mailboxes to CSV

In the Microsoft 365 admin center, go to Users > Active Users, then export users to CSV. That file includes User Principal Names (UPNs), which act as the main email addresses for each mailbox. Understanding the differences between Google Workspace vs Microsoft 365 for cold email can help you choose the right platform for your campaigns.

If you manage a larger team, PowerShell is often the easier route:

Get-Mailbox -ResultSize Unlimited | Select-Object UserPrincipalName | Export-Csv -Path "export.csv"

You also need to enable SMTP AUTH for each mailbox in Users > Active Users > [select user] > Mail > Manage email apps. Turn on IMAP for SMTP/IMAP logins, and use a 16-character app password for accounts protected by MFA.

Skip that step, and Icemail will reject the login with a 5.7.57 error.

Use a CSV format Icemail can map without issues

After you export the raw data, reshape it to match this schema before you upload it:

Save the CSV in UTF-8 encoding so names with accents or special characters don't get mangled.

Before uploading, clean up the file:

• Remove extra commas inside cells
• Delete duplicate rows
• Fix inconsistent date formats

Once the CSV is clean, upload it to Icemail and map the fields.

Import mailboxes into Icemail and connect sending accounts

Start by importing your mailbox CSV. Then connect each sending account.

Upload the CSV and map mailbox fields

Go to Icemail's mailbox provisioning section, upload the CSV, and map each row to the right sending domain, display name, and workspace. Following a comprehensive cold email infrastructure setup checklist ensures you don't miss critical configuration steps.

Before you confirm the import, double-check every mailbox. Make sure each one points to the right domain, sender name, and workspace. This is the best time to catch mix-ups. If you miss them here, you'll end up chasing setup issues later.

Icemail uses one workspace per domain. That setup keeps mailboxes for each domain separate, so if one account gets flagged, it won't spill over into the others.

Connect inboxes with SMTP/IMAP or OAuth

For Google Workspace or Microsoft 365, use OAuth. Connect the accounts from the admin panel, and make sure 2FA is enabled on the domain.

If you need direct server control, use SMTP/IMAP instead. Enter the host, port, and app password for each mailbox. Icemail checks the login during setup, so you'll know right away if something's off.

Once the accounts are connected, move on to DNS and deliverability checks before you send your first campaign.

Check DNS, deliverability, and sending settings before launch

Now that your mailboxes are connected, do a quick setup check before you send a single email. This part matters more than most people think. A solid offer won't help much if your DNS is off or your sending volume trips a filter on day one.

Icemail.ai automates DNS checks for connected mailboxes, which keeps the process fast and all in one place.

Confirm SPF, DKIM, and DMARC records

Here's the bare minimum to have in place before sending:

• One SPF record per domain. If your domain already has one, edit that record instead of adding a second SPF entry.
• A valid DKIM selector. Copy the DNS value exactly as shown during setup.
• Set DMARC to p=none during validation.

This is one of those places where small mistakes can snowball. An extra SPF record or a DKIM value pasted wrong can lead to delivery issues right out of the gate.

Run quick deliverability checks before sending

Before you import your list, verify it with ZeroBounce or MillionVerifier. It's a simple step, but it can save you from hard bounces, complaints, and wasted sends. Using best email verification tools helps maintain your sender reputation from the start.

Use these launch thresholds:

If an inbox is new, or you just imported it, go slow. Start at 5 emails per day per inbox, then add 5 emails per day over the next three weeks until you get close to the 50-email-per-day cap.

That gradual ramp-up helps your inbox look like normal human activity instead of a switch flipping from zero to full blast.

Set sending windows and daily limits for US outreach

Inside Icemail's campaign settings, set daily caps for each inbox and keep sending locked to U.S. business hours. That helps your activity look more natural. For larger campaigns, learn about scaling cold email with multiple mailboxes to maintain deliverability as you grow.

A few guardrails here make a big difference:

• Keep 3–4 mailboxes per domain
• Do not exceed 5

Once your limits and sending windows are in place, you're ready to import prospects and build your first sequence.

Import prospects and launch your first Icemail campaign

With your mailboxes connected and your sending limits in place, the last step is simple: bring your prospect list into Icemail and turn on your first sequence.

Upload your prospect CSV and map contact fields

Your prospect CSV should include an email column, plus any fields you want to use for personalization. Before you upload it, clean up the file, keep the formatting consistent, and make sure each column name is clear.

When you upload the CSV in Icemail, use the field mapper to match each column header to the correct contact property. Check each mapping carefully before moving on. If one column is off, your emails can pull in the wrong name, company, or detail. That kind of mistake is easy to miss at first and annoying to fix once messages start going out.

After the fields are mapped, go right into your first send.

Build a short first sequence and launch safely

Keep the first sequence short and simple. Choose your connected mailboxes as the sending pool.

Start with a small send, turn on reply, bounce, and unsubscribe handling, then launch.