Zoho Mail to KAGOYA MAIL Migration Guide — DNS, Authentication & Data Audit in Practice

Want to migrate from Zoho Workplace to another email service but worried about DNS and email authentication settings? This practical guide walks you through the process. Using the migration from Zoho Mail to KAGOYA MAIL as an example, we cover DNS switchover, SPF/DKIM authentication, and data auditing of the old service.

Does This Sound Like Your Situation?

Zoho Workplace is a groupware suite bundling Mail, WorkDrive, Cliq, Calendar, and many other services. But have you found yourself in a situation like this?

• You’re only using the email feature but paying for the entire groupware suite
• File storage has already been migrated to another service (Nextcloud, Google Drive, etc.)
• The per-user pricing model becomes a burden as your team grows

In cases like these, migrating to an email-only service becomes a viable option.

Why KAGOYA MAIL?

KAGOYA MAIL is an email-only service designed for business use. Here’s what to consider:

• Dedicated virtual server with dedicated IP — Unlike shared hosting with WordPress, your email delivery rate and stability are higher
• Flat-rate pricing with unlimited users — Unlike Zoho’s per-user pricing, you can add accounts freely
• Domestic servers with a strong track record in enterprise use, standard SPF/DKIM/DMARC support
• IMAP/SMTP support lets you keep using existing email clients

The Bronze plan is ¥3,300/month (¥2,640/month with annual billing). Compared to Zoho Workplace Standard (¥1,440/month for 3 users), the raw cost is higher, but considering the dedicated email environment, dedicated IP, and unlimited users, it’s worth considering as an investment in email reliability.

STEP 1: Prepare the Destination

Add your custom domain and create email accounts in the KAGOYA control panel.

1. Domain Settings → Add Custom Domain to register your domain
2. Set the default delivery setting to “Treat as error” (for mail to non-existent addresses)
3. Create the required email accounts

STEP 2: Export Zoho Email Data

Export email data from the Zoho Mail admin panel, account by account.

1. Go to Admin Panel → Data Management → Export Mailbox
2. Select the target account and start the export
3. Download the ZIP file once generated

The ZIP contains email files in EML format. Depending on the number of accounts and volume of emails, the export may take several tens of minutes, so plan accordingly.

STEP 3: IMAP Import

Import the exported EML files to the destination IMAP server. Doing this manually is tedious, so automating with a Python script is recommended.

import imaplib
import email
import glob

# KAGOYA IMAP connection
imap = imaplib.IMAP4_SSL("mail-server-name", 993)
imap.login("account-name", "password")
imap.select("INBOX")

# Bulk upload EML files
for eml_path in glob.glob("export/**/*.eml", recursive=True):
    with open(eml_path, "rb") as f:
        msg = f.read()
    imap.append("INBOX", None, None, msg)

imap.logout()

STEP 4: DNS Switchover

Change the DNS records to redirect email delivery. This example uses Cloudflare, but the settings are the same regardless of DNS provider.

MX Records

Delete the Zoho MX records (mx.zoho.jp / mx2.zoho.jp / mx3.zoho.jp) and register the new mail server. For KAGOYA MAIL:

SPF Record

v=spf1 include:kagoya.net ~all

Change the old include:zoho.jp to include:kagoya.net.

DKIM Record

Obtain the public key from the DKIM Settings in the KAGOYA control panel and register it as a TXT record.

Delete the old zmail._domainkey (Zoho) record.

DMARC Record

v=DMARC1; p=quarantine; rua=mailto:(report address)

Upgrading the policy from none to quarantine strengthens spoofing prevention.

STEP 5: Send/Receive Testing

After switching DNS, always verify these four points:

1. Can you receive from external? — Send a test email from Gmail, etc.
2. Can you send externally? — Send from KAGOYA to Gmail, etc.
3. SPF PASS — Check for spf=pass in the received email headers
4. DKIM PASS — Check for dkim=pass in the received email headers

Email header verification can be automated with Python. SPF/DKIM PASS confirmation in particular is easy to miss visually, so extracting via script is more reliable.

import imaplib
import email

imap = imaplib.IMAP4_SSL("mail-server-name", 993)
imap.login("account-name", "password")
imap.select("INBOX")
_, data = imap.search(None, "ALL")

for num in data[0].split()[-3:]:  # Latest 3 emails
    _, msg_data = imap.fetch(num, "(RFC822)")
    msg = email.message_from_bytes(msg_data[0][1])
    auth = msg.get("Authentication-Results", "")
    print(f"Subject: {msg['Subject']}")
    print(f"Auth: {auth[:200]}")
    print()

imap.logout()

STEP 6: Old Service Data Audit

Zoho Workplace bundles many services beyond email, including WorkDrive, Cliq, Calendar, and Contacts. Before canceling, verify that no data remains in each service.

Services to Check and Decision Criteria

WorkDrive Gotcha: Trash Consuming Storage

An easily overlooked issue is WorkDrive’s trash. In our case, the admin panel showed approximately 45 GB of storage usage, but opening the folders showed “No items.”

The cause: all data was sitting in Team Folder trash. Data deleted during the previous Nextcloud migration had remained in the trash the entire time.

The admin panel storage display includes data in trash. “Storage in use ≠ data that needs to be backed up,” so check the trash before making decisions.

STEP 7: Cancel Zoho Subscription

Once the data audit is complete and send/receive at the new service is working properly, proceed with cancellation.

1. Open Zoho Mail Admin Panel → Subscription Management → Overview
2. Click the Subscription Management link to go to Zoho Store
3. Click Change Plan
4. At the bottom of the page, click Cancel Subscription
5. Select a reason and confirm Switch to Free Plan

If “Automatically downgrade at the end of the current billing period” is checked, you can continue using paid plan features until the period ends, after which it automatically transitions to the free plan. To keep a safety net for rollback, we recommend not deleting immediately and observing on the free plan for a while.

Takeaways

1. Shorten DNS TTL in advance to minimize impact during the switchover
2. Both SPF and DKIM are essential. Having only one increases the risk of being flagged as spam, especially by Gmail
3. Watch out for “visible but unnecessary” data during old service audits. Trash and version history can silently consume storage
4. Save receipts and invoices before canceling. You won’t be able to retrieve them after deleting the account
5. Choose based on “what needs to be separated,” not “what’s cheapest.” Email is a business lifeline, and investing in a dedicated environment is worthwhile

Email migration touches a wide range of areas — DNS, email authentication — making it psychologically daunting. But at the end of the day, it’s just about correctly setting four types of records: MX, SPF, DKIM, and DMARC. Follow the steps in this guide, checking each one along the way.