KB Article: MailHostingService.com Shutdown - Migration Guide

Overview

MailHostingService.com has been permanently discontinued as of September 30, 2025. All email sent to domains previously hosted on this platform (MX: mx1.mailhostingservice.com) is now receiving a deferral response with error code 450 4.7.1 and the message "We no longer relay <domain>".

Critical: We are not rejecting emails outright. Instead, we are asking sending servers to defer delivery. This means incoming emails will be queued on the sending email server until they time out. We have no control over how long sending servers will continue to queue messages before timing out. Once these queued messages time out, they will be permanently unrecoverable.

This article provides step-by-step instructions for migrating to a new email provider.

Symptoms

• Emails bouncing with error: 450 4.7.1 We no longer relay <domain> - see https://www.mailhostingservice.com/
• Cannot access webmail at mailhostingservice.com
• Email clients showing connection errors
• Contact forms on websites not delivering messages

Resolution Steps

Step 1: Choose a New Email Provider

Select one of these recommended providers:

Step 2: Pre-Migration Checklist

Before starting migration, document the following:

• List of all email accounts
• Email aliases and distribution lists
• Email forwarding rules
• Email signatures
• Integrated services (CRM, ticketing systems)
• Current DNS settings (SPF, DKIM, DMARC)

Step 3: Create New Email Accounts

1. Sign up for your chosen provider
2. Create user accounts (match existing usernames when possible)
3. Set temporary passwords
4. Require password change on first login

Step 4: Backup Existing Data (If Still Accessible)

Via Email Client (IMAP):

1. Open email client (Outlook, Thunderbird, Mail app)
2. Ensure account is set to IMAP (not POP3)
3. Select all folders
4. Drag to local folders or export as PST/MBOX

Items to Backup:

• All email folders
• Contacts
• Calendar entries
• Tasks/Notes
• Email rules/filters

Step 5: Prepare DNS Changes

1. Login to DNS provider (domain registrar or DNS host)
2. Lower TTL to 300 seconds (5 minutes) on existing MX records
3. Document current MX records before removing

Step 6: Update MX Records

Remove old records:

Priority: 10, Server: mx1.mailhostingservice.com
Priority: 20, Server: mx2.mailhostingservice.com

Add new provider's MX records:

Priority: 1, Server: aspmx.l.google.com
Priority: 5, Server: alt1.aspmx.l.google.com
Priority: 5, Server: alt2.aspmx.l.google.com
Priority: 10, Server: alt3.aspmx.l.google.com
Priority: 10, Server: alt4.aspmx.l.google.com

Priority: 0, Server: [domain]-com.mail.protection.outlook.com

Step 7: Configure Email Authentication

Update SPF Record:

Remove: include:spf.mailhostingservice.com
Add: [new provider's SPF include]

Configure DKIM:

• Follow new provider's DKIM setup guide
• Add DKIM keys to DNS

Update DMARC (if applicable):

• Ensure rua/ruf addresses are still valid

Step 8: Migrate Email Data

Option A: Provider Migration Tool

• Most providers offer free migration services
• Requires IMAP credentials from old service

Option B: Manual IMAP Upload

1. Add new account to email client
2. Drag folders from old account to new
3. Verify all data transferred

Step 9: Update Email Clients & Devices

Desktop Clients:

• Remove old account
• Add new account with provider's settings
• Test send/receive

Mobile Devices:

• Delete old account
• Add new account
• Verify sync settings

Webmail Bookmarks:

• Update to new provider's webmail URL

Step 10: Post-Migration Tasks

• Update email on all online accounts
• Update contact forms on websites
• Configure scan-to-email on printers/scanners
• Update email in signature blocks
• Notify frequent correspondents
• Update marketing/mailing list platforms
• Test autoresponders
• Verify calendar sharing still works
• Update 2FA recovery emails
• Cancel mailhostingservice.com billing

Important Notices

Common Issues

Email Still Bouncing After MX Update

• Cause: DNS propagation delay
• Solution: Wait 24-48 hours, check DNS with dig or nslookup

Cannot Access Old Emails

• Cause: Service already terminated
• Solution: No recovery possible if access already lost

Website Contact Form Not Working

• Cause: Form configured to send through old email
• Solution: Update form settings or SMTP configuration

Email Clients Showing Certificate Errors

• Cause: Still configured for old servers
• Solution: Remove and re-add account with new settings

Support Information

Affected Domain Check:
https://logs.duocircle.com/v2/?page=index&unsetfilter=all&search=no+longer+relay

Reference Code: MAILHOSTING-SHUTDOWN-2025

Related Articles:

• KB-DNS-001: How to Update MX Records
• KB-EMAIL-001: Email Client Configuration Guide
• KB-SPF-001: SPF Record Best Practices

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