What does a secure email migration mean?
Secure email migration means moving mailboxes, domains, DNS records, archives, permissions and safeguards without losing correspondence or creating confusion for users. Virtline plans the migration window, tests mail flow, configures SPF, DKIM and DMARC, and verifies deliverability, access and user support after the switchover.
- Scope: mailboxes, aliases, archives, contacts, calendars and delegation, including tool limitations.
- Cutover conditions: backup, recovery test, MFA, routing, domain authentication and pilot acceptance.
- Acceptance: completeness report, email and application tests, open exceptions and an operations owner.
Mail migration, or why move your mailbox to the Google or Microsoft mail platform?
Transfer coverage depends on the source, destination and migration tool. IMAP migration moves messages and mail folders but does not itself transfer contacts, calendars or tasks. Rules, delegation, archives and other data need separate verification and testing. Match destination licences and features to the operating model.
Microsoft 365
Exchange Online, Teams, OneDrive and SharePoint as the target email and collaboration environment.
Google Workspace
Gmail on the company domain, Google Drive, calendars and user account administration.
Migration consultation
We check the current email, domains, data volume, SMTP applications and switching plan.
When is email migration a high-risk project?
The risk increases when a company has multiple domains, old IMAP mailboxes, shared mailboxes, local archives, applications sending SMTP messages, delegated calendars or users working outside the office. Then, switching mail without inventory can stop sales, invoicing, customer service and supplier communications.
Mailbox inventory
We count accounts, aliases, groups, shared mailboxes, archives, SMTP applications and data owners.
Domain security
We organise SPF, DKIM, DMARC, anti-spam policies, MFA and administrator access.
Continuity of work
Before the change, we create a backup and define a rollback plan in case testing reveals a problem.
What needs to be decided before moving mailboxes
A good migration starts with decisions that are usually overlooked: who owns the domain, where the provider's responsibility ends, what data should be transferred, how long to store archives, and whether the new platform should immediately enforce MFA and retention rules.
Target platform
We select Microsoft 365, Google Workspace or a hybrid variant according to the licence, application and work model.
Access and MFA
We set SSO, MFA, administrator accounts, access recovery and rules for mobile devices.
Mail sending applications
We check scanners, CRM, ERP, invoicing systems, monitoring and applications using SMTP.
Retention and compliance
We take into account GDPR, archiving, customer requirements and evidence needed during an audit.
What actions are we taking to migrate data to the cloud?
The migration process includes verification of customer needs, licence activation, data backup, creation of user accounts, licence assignment, checking the corporate domain, data migration, administration panel configuration and email completeness tests after transfer.
- We verify email parameters, number of mailboxes, aliases, contacts, calendars, rules and folders.
- We back up the data to be migrated before synchronisation and the DNS cutover.
- We create user accounts, assign licences and configure the administration panel as agreed.
- We adapt the company domain to the new email platform, including MX, SPF, DKIM, DMARC and autodiscover.
- We test correct operation, completeness of mail, sending, receiving, calendars and user access.
Phased decision map for email migration
Prepare backup, recovery testing, MFA, permissions and domain protection before a pilot using real data. Timing depends on mailbox count and source limitations; 30/60/90-day reviews are examples of progress checks, not delays to safeguards.
- 30-day review: approve inventory, data scope, licences, DNS ownership and safeguard readiness.
- 60-day review: assess the pilot, data completeness, SMTP applications, SPF/DKIM/DMARC and recovery.
- 90-day review: review migration waves, cutover, deliverability, queues and remaining exceptions.
- After cutover: reconcile data received by both environments, confirm completeness and only then close former access.
The most common mistakes when migrating email
Typical errors include missing backups, unclear DNS permissions, lowering TTL too late, omitted aliases, unlisted senders and missing tests. If the plan requires a lower TTL, change it in advance and wait at least the previous TTL before changing MX. Lowering the value does not clear records already cached by DNS servers.
No procedure for returning to the previous email system
Rollback covers routing and reconciliation of messages received by both environments. Reverting MX alone neither recovers data nor reverses synchronisation.
Invisible integrations
Monitoring systems, scanners, and business applications often send mail outside of primary mailboxes.
Poor security
A new platform without MFA, DKIM and DMARC only transfers old risks to the cloud.
Controlled cutover acceptance criteria
Cutover requires pilot acceptance, a backup test, account protection and verified mail flow. Keeping addresses depends on domain control and agreed account naming. Connectors and clients must use supported authentication and encryption; compatibility is checked before the change.
- Mail receiving and sending can continue to operate in the existing environment until the implementation is complete.
- The email address may remain unchanged unless the company consciously changes the domain or account naming.
- The client prepares a set of access data and permissions to transfer the mailboxes within the agreed scope.
- After migration, Virtline can take over the administration of accounts, configuration, updates and ongoing security control.
What does the customer gain by migrating email to the Google or Microsoft cloud?
The company gains larger inbox capacity, message archiving, automatic rules, integration with other cloud applications and an administration panel for creating, deleting and controlling accounts. This makes it easier to monitor calendars, manage access, and maintain email as a business service rather than a single server.
How Virtline conducts email migration
We combine Microsoft 365 administration, email security and infrastructure support. Before the switchover, we prepare a technical checklist, schedule, list of owners, communication plan for users and evidence of work completion. After migration, we can take over ongoing maintenance: licences, accounts, policies, backup, monitoring and incident response.
Pre-migration audit
We check the current server, DNS, data volume, SMTP applications and risks to business continuity.
Security configuration
We set domain security, anti-spam, MFA, administrative roles and basic access policies.
Maintenance after the project
After migration, we can conduct email administration as part of ongoing IT support.
Related services for email migration
These areas link mailbox migration to implementation, security and ongoing maintenance decisions.
Mail servers
Design and maintenance of Exchange, Microsoft 365, Postfix and hybrid environments.
Email security
Protection against phishing, spoofing and malicious attachments after migration.
Microsoft 365
Identity, email, Teams, SharePoint and access policies in one maintenance model.
Contact
Use the consultation to agree mailbox inventory, DNS ownership, security configuration, backup, migration window and post-migration support.
