Office 365 migration for 800 users over 1 weekend

This marketing services group develop multichannel marketing campaigns for global brands. The company thrives off innovation, and as a result are constantly looking for ways to improve their existing business processes.

Customer challenges

  • Vulnerabilities on existing Exchange 2010 mail solution

  • Outdated email server infrastructure and Office software

  • The need to;

    • Reduce running costs on infrastructure upgrades and maintenance

    • Share and collaborate with other users with ease

    • Provide better mobility for remote users accessing data

    • Become compliant with GDPR security measures

Port-365 solution

Port-365, is the complete Office 365 migration solution from Port-P.        For this client, the Port-365 solution included;

  • Project planning

  • Pre-migration testing

  • Migration of the client's on-premise Exchange server to the cloud

  • Post-migration support

Photo by Stepan_Bormotov/iStock / Getty Images

Customer Engagement 

Maximising productivity while minimising costs

After listening to our client’s challenges and requirements, the first stage in the migration process was to determine which Office 365 plan would best fit their needs. With 800 employees on site, working across a range of job functions including factory workers, designers, and commercial support staff, licenses were going to involve various functions and a significant investment.

Port-365 identified the key requirements in our client’s working environment and created an optimised licensing model to both save money and utilise only the required features. The model included the purchase of two license types: Office 365 E1 (for employees who didn’t need continuous computer access) and Office 365 E3 (for employees who needed installable applications and constant email access).

Laying the foundations for a successful migration

Office 365 migrations are complex tasks and it was therefore essential to gain a detailed understanding of our client’s existing environment to develop a detailed migration plan which would ensure the process ran as smoothly as possible.

Thorough analysis

Before work commenced, a Port-365 migration specialist conducted a full analysis of our client’s existing infrastructure using Microsoft Health, Readiness and Connectivity Checks tools. This was to determine if their existing hardware was configured correctly and if it would be compatible with any proposed Office 365 solution.

Port-365 also facilitated a collaboration between the client and Microsoft FastTrack. The Microsoft FastTrack team aim to make the migration process as quick, easy and seamless as possible by offering guidance to ensure every stage of the migration process is completed through a Microsoft best practice approach.

Addressing concerns

As with all businesses, our client’s data is invaluable, and it was a huge concern for both parties that the data would be lost or corrupted during the migration process. Working closely to address this concern, Port-365 created a hybrid link between the existing on-premise Exchange server and the new Office 365 infrastructure to test the connection was secure and ensure that no data would be lost. The hybrid link also allowed for testing of both the old and new environments to guarantee they were not adversely affected by each other during the pre-migration pilot testing.

Comprehensive pre-migration pilot testing

To further prove the hybrid link was stable and working, Port-365 ran a pilot migration which involved creating a test environment to migrate dummy user accounts from the existing server to the cloud. The dummy accounts were then migrated back from the cloud to the existing server as it was imperative there was a remediation plan in case problems arose during the migration.

The testing also acted as a benchmark as it measured the WAN bandwidth capabilities of our client’s connections and as a result meant an accurate completion date could be proposed. This method of testing went above and beyond the Microsoft best practice approach to ensure our client felt completely at ease.

1 weekend = 800 users live

Following the successful pilot testing, Port-365 then managed the entire migration process of on-premise mailboxes to the cloud, seeing over 800 users migrate over one weekend. To ensure the migration ran smoothly, the 800 users were split into batches and moved across batch at a time. As a result of the rigorous pre-migration testing the migration was completed well ahead of schedule within a 12-hour window.

To eliminate the complexities involved in having 2 main Exchange systems running simultaneously for a prolonged period, a cutover migration was chosen. This migration created a seamless transition, as it minimised downtime to business operations with employees leaving the office on Friday evening using on-premise Exchange and returning on Monday with Office 365. Employees were well aware of what to expect from the migration, thanks to the bespoke internal communications plan Port-365 had developed, advising our client on what to inform their end users about the changes to come.

Full Port-365 support package

Following the migration weekend, a Port-365 specialist provided onsite support including manual mailbox configuration and ensuring any user queries were handled immediately – which allowed all employees to get onboard with the new system and back to their normal methods of working as quickly as possible.


Migration success

The migration was an overwhelming success. Office 365 has provided our client with a more efficient and cost-effective way of operating. It's also provided them with more intelligent ways to handle the sharing of data and utilise mobility, as well as providing added data security measures in line with GDPR requirements. 

Post migration, the Port-365 helpdesk offers 24/7 first line support for any technical queries, while raising second and third line support queries directly to Microsoft. Port-365 as a CSP also provide our client with any additional licenses they require.


This client is happy to act as a reference for Port-365. Please contact us if you would like to arrange a time to chat.