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Mail migration from Outlook to Exchange Online

18 January 2022

The Faculty of Science will step by step use the new mail environment Exchange Online. On Monday 24 January 2022 the ISSC will migrate all Outlook mailboxes and calendars of the Faculty Support Staff to Exchange Online. The shared 'functional' mailboxes will also be migrated. Do you only use a personal mailbox and calendar in Outlook? If so, you do not have to do anything yourself. The migration process takes place in the background and your mailbox and calendar will remain available. The migration is expected to be completed before 10.00 a.m. on Monday 24 January. During this period you can continue work as usual.     

Why are we migrating to Exchange Online?

The transition to Exchange Online makes it possible to integrate Office 365 applications and to use new apps, such as the Outlook app, Planner and To Do. Security will be increased and better protection will be offered against phishing emails. The size of the mailbox will expand, so it is no longer necessary to send individual requests to expand the mailbox. 

How can I prepare for mail migration?

  • You may have linked other mailboxes in addition to your own mailbox. Make sure to note down the name of this mailbox beforehand so that it can be added again after the migration. 

  • Download the Outlook app for your mobile if you want to synchronise your mail, calendar or contacts. You can find this in the Play Store (for Android Phones) or the App Store (for iPhone Phones)  

What will I notice after the migration?

  • Your regular mailbox, archive folders and agenda on your university (managed) PC or laptop are automatically transferred to the new mail environment and are immediately available in Outlook. Mailboxes that you manage in addition to your own mailbox, so-called functional (or shared) mailboxes, are no longer linked and must be added again. You can find information on how to add these functional boxes to your account in the Helpdesk portal

  • You can now also use the Outlook app on your phone, tablet or own device. You can also continue to use your current mail app, but you will then have to link your mailbox again. This also applies to other operating systems such as Mac and Linux. 

  • You can find your webmail in your browser if you log in to office.com and then choose the Outlook Online app.  

  • Should you have to log in again, it concerns an Office 365 login and you will also be asked for your MultiFactor Authentication

  • If an email has been sent to you that is considered suspicious by Microsoft (spam, fishing, etc), you will receive an email informing you that one or more messages have been placed in quarantine. The mail is repeated every three days. The sender of this message is: quarantine@messaging.microsoft.com. You can still access these emails in a separate quarantine environment

Extra information if you use a functional mailbox

Functional mailboxes are widely used. These are migrated before the migration. However, it could be that a functional mailbox is migrated but a personal account has not been migrated yet, which means you cannot access the functional mailbox. This is relevant for functional mailboxes to which not only support staff but also support staff of institutes have access to. The mailboxes of support staff of institutes who have not been migrated yet cannot use the functional mailbox temporarily. If this is the case, please contact the ISSC. 


If you have any problems as a result of the migration, please contact the helpdesk via helpdesk@issc.leidenuniv.nl or send a message via the helpdesk portal

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