How to Migrate GoDaddy Email to Office 365

Most teams asking "how do I move from GoDaddy to Office 365" don't actually know which GoDaddy product they're on. GoDaddy resells two completely different mail platforms: its own legacy Workspace Email (an IMAP-based service) and Microsoft 365 itself, branded inside GoDaddy's billing portal. The migration path is different for each, and getting that wrong is the most common source of wasted time on these projects. This guide covers both, with the IMAP path as the default because that's the one most domains on GoDaddy end up needing.

Identify the source product first#

Sign in to the GoDaddy account that owns the domain. In My Products, look at the email section.

GoDaddy Workspace Email. Listed as "Workspace Email" or "Email" with mailbox plans. This is GoDaddy's legacy IMAP mail product. It has its own webmail at email.secureserver.net, uses imap.secureserver.net for IMAP and smtpout.secureserver.net for outbound SMTP, and is not Microsoft anything. This is the most common case for older small business domains.

Microsoft 365 from GoDaddy. Listed as "Microsoft 365" with plans like "Email Essentials" or "Business Professional." This is a real Microsoft 365 tenant, but it sits inside GoDaddy's CSP partner relationship. You don't get the standard admin.microsoft.com access without first removing the partner relationship.

If you're on Workspace Email, the rest of this guide applies directly: it's a standard IMAP migration into Office 365. If you're on Microsoft 365 from GoDaddy, you have two viable paths: remove the partner relationship and run a tenant-to-tenant migration, or fall back to IMAP migration into a separate Microsoft 365 tenant you control. The IMAP path is faster to start and is what most MSPs default to when speed matters more than fidelity.

Before you start#

A few prerequisites apply regardless of source product:

• A target Microsoft 365 tenant that is not the same one being migrated from. The domain must be added and verified.
• Exchange Online licenses assigned to each destination user, with mailboxes provisioned.
• Source credentials for every mailbox: either the working password or, if 2-Step Verification is enabled at GoDaddy, an app password.
• Admin access to the GoDaddy DNS zone for the domain. This is non-negotiable for cutover.
• A pilot of two test mailboxes to validate IMAP connectivity and per-user behavior before the main batch.

Throttling and concurrency on GoDaddy#

GoDaddy Workspace Email throttles IMAP aggressively. The exact thresholds aren't published, but in practice you can count on:

• A soft cap of around 10 simultaneous connections per source IP. Exceeding it triggers temporary connection refusals lasting minutes to hours.
• Per-mailbox connection rate limiting that punishes tools that open and close connections rapidly.
• Occasional Too many simultaneous connections rejections during peak hours that resolve themselves overnight.

Set the IMAP migration endpoint's MaxConcurrentMigrations to 5 for the first batch, with MaxConcurrentIncrementalSyncs also at 5. If the first batch completes cleanly you can raise it for subsequent batches, but raising it above 10 rarely helps and frequently causes batches to fail in messy ways.

Migration steps#

1. Identify which GoDaddy mail product you're on

   Sign in to the GoDaddy account and check whether the domain is using Workspace Email or Microsoft 365 from GoDaddy. The remaining steps assume Workspace Email; if you're on Microsoft 365 from GoDaddy and want a true tenant-to-tenant migration, request release of the partner relationship from GoDaddy first.

   If you intend to fall back to IMAP migration even from a GoDaddy-hosted Microsoft 365 tenant, you can — but you'll lose calendar and rules in the move, just like with Workspace Email.

2. Prepare the target Office 365 tenant

   In the target tenant, add the domain in the Microsoft 365 admin center and complete the TXT verification. Don't change MX yet — only the TXT record for verification. Assign Exchange Online licenses to each destination user and provision the mailboxes (signing in to Outlook on the web once is enough).

   If the destination tenant already serves another domain, double-check that the new domain is set as Accepted but Not Default unless that's what you want.

3. Collect source credentials

   For each mailbox in scope, gather the source IMAP credential. If 2SV is enabled at GoDaddy for the account, an app password is required — the regular password will not authenticate over IMAP. Track this in your CSV preparation document; missing credentials is the single largest source of mid-batch failures.

   For environments with many users, generate app passwords during a quiet window and store them temporarily in a password manager that supports controlled sharing.

4. Test IMAP connectivity to GoDaddy

   From Exchange Online PowerShell in the target tenant, run:

   Test-MigrationServerAvailability -IMAP -RemoteServer imap.secureserver.net -Port 993 -Security Tls

   A success result confirms the path is clean. A failure is almost always one of: wrong port, TLS version mismatch, or — rarely — a firewall on the destination tenant's outbound path. Fix it here, not later in the batch.

5. Build the CSV and create the migration endpoint

   Build a CSV mapping file with one row per mailbox: source email address, destination user, source password. Save as UTF-8.

   In the Exchange Admin Center, go to Migration → Endpoints and add a new IMAP endpoint with these values:

   • Server: imap.secureserver.net
   • Port: 993
   • Security: TLS
   • MaxConcurrentMigrations: 5
   • MaxConcurrentIncrementalSyncs: 5

   EAC runs a connection test before saving. A failure here is the same root cause as step 4.

6. Create and start the migration batch

   In EAC under Migration, create a new batch, choose IMAP, attach the CSV, select the endpoint, and target the destination domain. Start the batch manually for the first batch so you can verify configuration. The batch enters Syncing, then Synced when initial sync completes.

   Incremental sync runs every 24 hours after initial sync completes, picking up new mail that lands on GoDaddy until you finalize the batch.

7. Monitor and retry failures

   EAC shows per-mailbox status. Mailboxes in Failed or Synced With Errors should be inspected for the underlying error and retried individually. The most common GoDaddy-specific failures are:

   • AUTHENTICATIONFAILED from a wrong or missing app password.
   • Too many simultaneous connections if concurrency is too high.
   • Folder name issues for mailboxes with non-ASCII folder names.

   The too-many-IMAP-connections fix covers the concurrency problem in more depth than fits here, and the IMAP protocol glossary explains the underlying port and TLS semantics.

8. Cut over DNS at GoDaddy

   48 hours before cutover, lower the TTL on the MX, Autodiscover, SPF and DKIM records at GoDaddy to 300 seconds. On cutover day, change these records:

   • MX → the value listed in your Microsoft 365 admin center, usually <tenant>.mail.protection.outlook.com with priority 0.
   • Autodiscover CNAME → autodiscover.outlook.com.
   • SPF TXT → v=spf1 include:spf.protection.outlook.com -all (merge with any existing senders).
   • DKIM CNAMEs → values from Microsoft 365 Defender's DKIM page, two CNAMEs per domain.

   Wait for propagation (usually 15–60 minutes with low TTL), confirm mail flow at the new tenant by sending a test from outside, then complete the batch in EAC.

Gotchas specific to GoDaddy#

A handful of issues come up consistently on GoDaddy to Office 365 migrations.

Workspace Email size limits. GoDaddy Workspace Email has historically capped mailboxes at smaller sizes than Office 365. If a user has been on the highest GoDaddy plan and is at 25 GB, plan on a long initial sync. Office 365 will accept the data; the source IMAP server will be the bottleneck.

App password expiry. App passwords on GoDaddy can be revoked by the user without warning. If a batch starts failing for a single user mid-run with AUTHENTICATIONFAILED, check whether they regenerated their security settings in the GoDaddy portal. This happens more often than you'd expect when users are nervous about a migration.

DNS records GoDaddy auto-manages. Domains registered at GoDaddy that have email through GoDaddy often have DNS records GoDaddy created automatically (Autodiscover CNAMEs, SPF includes). These need to be removed or updated; otherwise Outlook on the destination side will follow Autodiscover into a GoDaddy endpoint that no longer hosts the mailbox.

MX records and email forwarding. If users had GoDaddy-side forwarders or aliases, those don't carry across in the IMAP migration. Document them before cutover and recreate them as Office 365 mail flow rules or aliases on the destination side. The GoDaddy to Gmail walkthrough covers the same DNS records from the other direction if you're handling both moves in parallel.

Errors you'll actually see#

A short list of error strings worth recognizing.

• AUTHENTICATIONFAILED — missing or wrong app password on the GoDaddy side, or 2SV freshly enabled without one.
• Too many simultaneous connections — concurrency too high on the endpoint. Drop to 5 and retry.
• STARTTLS handshake failed — almost always the wrong port. GoDaddy IMAP is on 993 with implicit TLS, not 143 with STARTTLS.
• Folder UTF-7 conversion error — non-ASCII folder name on the source. Rename on the source mailbox.
• Message too large for destination — single item over Office 365's 150 MB per-message limit.

Communicating with users#

A short pre-migration note, three days before cutover, prevents most of the helpdesk volume. Tell users:

• The date and time of cutover.
• That they'll keep their current email address — only the back-end changes.
• That calendar and contacts on the source (if they used Workspace Webmail's calendar) are not migrating automatically and they should export them themselves with a step-by-step link.
• That on cutover morning they should sign in to Outlook on the web with their normal email address and the password the admin sets.

Send a second reminder the morning of cutover with the new sign-in URL and a short troubleshooting note pointing at common Outlook prompts (Modern Auth, MFA enrolment, password change at first sign-in).

FAQ#

For wider context on migration planning, cutover and validation, the complete email migration guide and the standard generic IMAP to Office 365 walkthrough cover material this provider-pair post leaves out. If your destination is Outlook on the desktop rather than Office 365 itself, the GoDaddy to Outlook walkthrough is the better fit.