Microsoft Exchange

By introducing Microsoft Exchange, we will provide all employees and students of the University of Mannheim with a standardized system for e-mails, calendars and address books. 

Accessing your Exchange mailbox

There are two ways to access your Exchange mailbox:

  1. via web mailer:
    Instructions for logging into the Outlook web app
  2. via an e-mail client:
    In order to work on your e-mails, meetings, and addresses in an e-mail client, we have created instructions on how you can add your Exchange mailbox to a client.


Here you will find the answers on frequently asked questions on migrating to and using Microsoft Exchange. 

  • Has my account already been migrated to the new Exchange mail system?

    Since 25 July 2022, new accounts are already on the new Exchange mail system.

    If you are unsure whether your mailbox has already been migrated to the new Exchange mail system of the university, you can verify this as follows:

    1. Go to in your web browser (e.g. Firefox, Chrome).
    2. Enter your Uni-ID in the field for user name and the password for your Uni-ID in the password field and click the login button.
      1. If you are able to login and see contents, your mailbox has already been migrated to the new Exchange system.
      2. If you are able to login but the mailbox is empty although contents should be there, the mailbox will shortly be migrated. Please go to your old mail box and check if you have received an e-mail about the migration. In this e-mail, the start and end date of the migration are specified.
      3. If you are unable to login, your mail account is still using one of the old mail systems. We will inform you about the upcoming migration of your mail account in due time.
  • What is my Exchange e-mail address?

    For looking up your Exchange e-mail address, please go to the Outlook web client in your web browser.

    Video instructions
    Please proceed as follows:

    1. Go to in your web browser.
    2. Login with your Uni-ID and the corresponding password.
    3. After the login, click on the profile picture in the upper right corner. Your e-mail address will be displayed in the pop-up window that opens.

    Due to the standard address structure, the subdomains (= the part of the address before the “” part, e.g. are no longer available for sending addresses. However, you can still receive e-mails that are sent to addresses containing a subdomain.

  • After the migration, some contents will no longer be displayed. Where can I find these contents?

    If you miss some contents after your mailbox has been moved to Exchange, please check if one of the following applies. If you have performed the check and are still unable to find the contents, please contact the IT support team at itsupport

    • “Gesendete Elemente” are missing
      Please check your folders in the new Exchange mail box. It may be possible that the folder “Gesendete Elemente” has been migrated with another (the original) name. After the migration, you may find this folder under “Sent” or “Sent items”. You can move the contents of this folder to the new “Gesendete Elemente” folder.

      If you have checked all your folders and are still unable to find that folder, this folder may have been empty in the old mail box -> empty folders will not be migrated. You can confirm this up to eight weeks after the migration. Please login to your old mailbox and check the folder there.
    • The folder“Gelöschte Elemente” is missing
      The folder “Gelöschte Elemente” or “Trash” will not be migrated, in accordance with its purpose. If you need elements from this folder, you can login to your old account and forward or download the contents within eight weeks after the migration.
    • Folders are missing
      Empty folders will not be migrated. You can create these folders in the new Exchange mailbox.
    • Certain e-mails are missing
      Please start by searching for the e-mail that seems to be missing.
    1. Please use the search in the web client and go to and do not search in Outlook on your computer.
    2. Please go to and login with your Uni-ID and the corresponding password.
    3. Go to the search bar in the upper left corner and enter one or two words from the e-mail or the subject of the e-mail. Please confirm the search by clicking on the magnifying glass.
    4. Please check if the e-mail appears in the search results.


    If you cannot find the e-mail, please keep the following in mind:
    Due to technical limitations, a very small number of e-mails cannot be migrated. The error rate usually is between 0.00% and 0.08%. This means that if your mailbox has 3,000 e-mails, on average one or two e-mails will not be migrated. If this happens when we are migrating your mailbox, we will send you a notification in which we list the relevant e-mails. Within eight weeks after the migration, you can go to your old mailbox and forward / download these e-mails.

    • Categories have not been migrated
      If you have used categories in Outlook, these categories will not appear in the new Outlook mailbox after the migration. In order to restore the settings, please go to the new Exchange mail box and create the same categories with exactly the same names as in your old mailbox. The migrated e-mails will then be automatically categorized and will match the same categories as in the old mailbox.
  • Why do my Outlook meetings not appear in Microsoft Teams and vice versa?

    The new Exchange mail system is not yet fully connected to the Microsoft 365 cloud services of the University, which include Teams. This means that your Microsoft Teams calendar and your Exchange calendar are currently two separate calendars that are not synchronized.

    The two calendars can only be combined after all mailboxes of the university have been migrated. Then the Teams calendar in the cloud and your Outlook calendar on the Exchange server will be combined and will be treated like a joint calendar.  We will inform you about the migration in due time.

    Information: This feature is not available on the M365 instance for students.

  • Why is it not possible to share my calendar?

    You can only share your calendar with persons with a “” address that are also in the domain “”. If you try to share your calendar with another domain, such as “”, sharing will be blocked as this is an external address.

    If you want to share your calendar within the domain of the University of Mannheim and receive an error message, please follow the instructions on how to share calendars.

  • Why is it not possible to use the official Outlook app?

    The official Outlook app for Android and iOS does not directly connect to the Exchange mail system of the university but to Microsoft servers that then connect with the mail system of the university. This way, some data are temporarily stored on Microsoft servers, including all e-mails from the last 30 days (for more information see
    This is not compatible with the university’s requirement to not store any e-mails in the cloud. Thus, the access for the official Outlook app is blocked.

  • Why does my e-mail not reach its recipients although I have already sent e-mails to these recipients in Outlook?

    If you migrated recently and are now using your new Exchange mailbox together with Outlook on your computer, your sent e-mails may not reach the recipients you contacted before the migration.

    This error occurs when you use temporarily stored addresses in the “To” or “CC” field. These old entries must be removed. After you have entered the addresses for the first time, the suggestions work as before. If you use Windows, please proceed as follows:

    1. Download the file „cache_adressen_entfernen.bat“.
    2. Close Outlook.
    3. Execute the file “cache_adressen_entfernen.bat“ by double-clicking on the file:
      If the file is blocked by Windows Defender or another antivirus software, please allow the file to be executed.
    4. Outlook will then start with an empty temporary storage for addresses and can be used as before.
    5. You can now delete the file.


    If you are on another operating system, you need to delete the addresses individually, when they appear. Then enter the address again once you have it deleted. You only have to enter the address once. Afterwards, the suggestions appear as they have before.


  • Why does the Outlook search not reveal my e-mail?

    The default setting is that Outlook searches the currently selected  mailbox when you start a search. If you have several mailboxes added to Outlook and the relevant e-mail is in another mailbox that you have not selected, this e-mail will not be displayed in the search results.

    In order to search all mailboxes at once, enter the search term, click “Current mailbox” at the left and then select “All mailboxes”.

    You can also set the default that all integrated mailboxes are searched at once. Please proceed as follows:

    1. Open Outlook on your computer.
    2. Click “File” in the upper left corner and “Options” in the lower left corner.
    3. Click on the “Search” tab in the window that opens.
    4. Select “All mailboxes” and confirm your selection by clicking the “OK” button:
  • What is the reason for not finding a contact in the Outlook address book?

    Please note: The Outlook address book only contains contacts of users that have already been migrated to Exchange or that use the administrations’s Exchange server (Verwaltungs-Exchange). During the migration, you might not find all contacts, since they may not have been migrated yet.

    If you are unable to find a contact in the Outlook address book and you are sure that this contact is in the address book, please proceed as follows:

    1. Open the Outlook address book.
    2. Make sure that the global address book and the option “All columns” have been selected.
    3. Enter the name into the search field and click on the arrow symbol.
  • Why am I unable to create Teams meetings in Outlook?

    End Outlook and MS Teams and restart both programs. If the problem continues to exist, reinstall MS Teams and end Outlook. After you have reinstalled Teams, start Teams and open Outlook.

    Information: This feature is not available on the M365 instance for students.

  • How can I make Outlook more accessible?

    For information on how to send and receive accessible e-mails, please refer to the instructions on Accessibility.

  • What do I have to keep in mind if I want to receive e-mails via mailing lists?

    If you want to receive e-mails via mailing lists, you do not have to do anything. After we have migrated your account to Exchange, you can still receive e-mails with your regular e-mail addresses. The e-mail address you entered in the mailing lists is still valid for receiving e-mails. The e-mails will be delivered to your new Exchange mail box.


  • What do I have to keep in mind if I want to send e-mails to mailing lists?

    After migrating to Exchange, you can only send e-mails with a sender address for your mailbox. If your sender e-mail has changed after the migration (please see: FAQ – What is my Exchange e-mail address?) and does no longer correspond to the e-mail address authorized as sender in the mailing list, please contact the administration or the mailing list and ask to enter your new e-mail address.


  • Do I have to change my e-mail certificate?

    Your e-mail certificate has been issued for one/several specific e-mail addresses and is only valid for these e-mail addresses. If your sender address is different after the migration (see: FAQ – What is my Exchange e-mail address?) and this new sender address is not covered by the certificate, you can no longer use this certificate and you have to get a new one. 

    You can see the e-mail addresses for which your certificate has been issued in the certificate application that you filled in. The addresses are specified in the application.

  • Is the POP3 protocol still available?

    No. The POP3 protocol is an old mail protocol which dates from a time in which storage capacity for individual mail accounts was very scarce.

    This means that POP3 comes with some restrictions. We have deactivated POP3 due to the following restriction:
    POP3 downloads the e-mails to the local computer of the user and deletes the e-mails in the Exchange mailbox. If the computer of the user is defective or there are other complications, these e-mails are lost without a backup and cannot be restored. If backups exists, they can only be restored to the last backup copy and some data are lost. Therefore, using POP3 for adding accounts of the Exchange mail system is not acceptable.

  • How can I display my academic title in Exchange?

    In order to have your academic title displayed in Exchange, go to the user administration website and check the relevant box under “E-mail | Uni-ID” → “Status Uni-ID”.  If you need to update the academic title that is displayed, please contact the human resources department at the University of Mannheim.

Information for admins
You are an admin at a chair or a university institution? We will provide you with all information required so that you can support your users as best as possible when migrating to the Exchange mail system.

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