CUMC Home | Columbia University | Jobs at CUMC | Contact CUMC | Find People
For support: call extension 5-Help (212-305-4357) or email us
  Email at CUMC


How do I get my CUMC email account?

Accounts must be requested by the employee or student's department or school. See Requesting an Account at the bottom of the main Email at CUMC page.

What should I do if I've forgotten, locked, or need to change my CUMC email account password?

Please use the myPassword site to instantly fix issues with your CUMC email account or password.
  • Log in to the site with your UNI first. See the FAQ immediately below if you are not sure of the difference between your CUMC email and UNI passwords.
  • Select the appropriate link to reset (if you've forgotten your password), change, or unlock your account.
If you have forgotten your password and did not already set up security questions on myPassword, or are not able to fix an issue, call us at extension 5-Help (212-305-4357) option 5.

IMPORTANT! Your CUMC email password syncs with your MC account if you have one. It does not sync with your UNI password, see the next FAQ for more details.

What is the difference between CUMC Exchange/Office 365 email, UNI, and MC accounts and passwords?
  • UNI accounts are provided to current Columbia faculty, staff and students. They are used to access University-wide resources such as myColumbia (payroll and benefits information) and Student Information Systems. See the Manage My UNI website for UNI password changes, resets, etc.
  • Exchange/Office 365 ( email accounts) and MC (computer logins) are specific to CUMC. They are part of a structure managed by CUMC IT called Active Directory, which centralizes accounts and the rights or "permissions" the account has to login to computers, network drives, and the Exchange/Office 365 mail system. They are essentially the same account, though not everyone with a CUMC email account will also be able to login to MC-connected computers. The myPassword site manages password changes, resets, etc. for both CUMC email and MC accounts.
For convenience, your UNI account ID or "username" is also used as your login for Exchange and MC, so you do not have to keep track of different IDs. However, your UNI and Exchange/MC passwords will not automatically synchronize when one is changed since they are separate systems. It is fine if you would like to use the same password for both to keep them "manually" synchronized.

After changing my password I can't open or send email from Outlook or my mobile device.

The email program on your computer or mobile device may store an old password, which can lock your account. See below to update your password in Outlook, or visit the Synchronize Your Password page for help with mobile devices.
    Outlook on Windows
  1. Select the File tab in the upper left corner of Outlook, then the Account Settings box/icon and the option to Add and remove accounts or change existing connection settings.
  2. In the Account Settings - E-mail Accounts window, make sure the E-mail tab is selected. Double-click on your CUMC Exchange email account listed under the Name heading (it will typically be called CUMC) to open the Change Account window.
  3. Clear out the Password field in the lower left and type in the new password you selected for your Exchange email account.
  4. Click the Next button in the lower right, then Close/Cancel and/or Finish to save the new password.
    Outlook on Mac
  1. Select Tools from Outlook's topmost menu bar.
  2. Select Accounts from the bottom of the Tools drop down menu.
  3. If there is more than one account listed in the left of the window, make sure your CUMC Exchange account is selected/highlighted.
  4. Clear the Password field and type in the new password you selected for your CUMC Exchange email account.
  5. Click the red button in the upper left corner of the Accounts window to close.
While it is convenient to let an email program store passwords, per University policy you should refrain from using this option.

What is the difference between and addresses?

For current CUMC faculty, staff and students, both addresses can be used to receive email, however only the CUMC address has storage space for your messages, attachments, contacts and related account data. This is also why email programs and apps can only be set up with your address.

The CUMC email system complies with regulations protecting ePHI and other requirements for the Columbia University Healthcare Component, while general accounts - on the LionMail/Google platform - do not have the required Business Associate Agreement. Due to this, CUMC affiliates are not allowed to store or automatically forward messages to another email account, including

How much space do I have in my CUMC email account?

Accounts have a default of 50GB of storage space.
This includes your mailbox and its contents (including email attachments), Calendar entries, and other items that you leave on the CUMC email system. Typically, anything you can see when using Web Outlook counts towards your storage space.

How large can email attachments be, and are there any types of attachments that can't be used?

An individual attachment can be up to 60MB.
  • IMPORTANT: The email message and any inline images, formatting, encoding (data added by email systems as the message is routed), etc., as well its attachment(s), counts towards the 60MB.
  • If an attachment or message is too large, Outlook will display a warning when you try to send it. The Storage and File Transfer page lists other options that can be used if needed.
Attachments can be almost any file type except:
  • Executables (files ending in ".exe")
  • Individually encrypted or password protected.
    This prevents the security filter on the CUMC email system from being able to scan for malicious programs. Secure email should be used to encrypt or otherwise protect sensitive attachments.

There may also be issues with attaching .xlsb (Excel Binary Workbook) files, please see the next FAQ for help.

Why did I get an Undeliverable - Message Size Violation error when I tried sending an .xlsb (Excel Binary Workbook) file?

Excel Binary Workbook files (those ending in .xlsb) use a type of compression. The CUMC email system detects the uncompressed size of the workbook if it is being attached to a message addressed to a non-CUMC email account. To share .xlsb files please use another method such as DatAnywhere, or try selecting a different file format when saving the file in Excel.

Can I use a program other than Outlook, such as Mac Mail?

To provide better support and security, Outlook is the only CUMC IT supported email program. Other programs are not as compatible with our email system while some features aren't available at all unless you are using Outlook. Mac users should be aware of known issues with Mac Mail, iCal and Exchange.

Current CUMC faculty, staff and students can install and use the full Microsoft Office Suite of programs, which includes Outlook, for free. There are versions for both Windows and Macintosh computers.

Why don't I see the same messages and folders in Outlook on my computer(s), Web Outlook and mobile devices?

CUMC email accounts have a main mailbox that "sits" on the email system, also referred to as the mail servers. Your mailbox and its subfolders (Inbox, Sent, Deleted, etc.) typically appear in your email program with as a list of folders, with the main mailbox at the top labeled with your full name or full email address.

Different programs that connect to your account - such as Outlook on a computer, the Web App, and a smartphone or tablet's email, calendar, contacts etc. - will show your mailbox messages and other contents that are on the mail server with a few important differences:
  • Settings in your mobile device typically don't download or show all messages and folders in order to save bandwidth and space on the device. This can be adjusted (refer to your device's instructions for help), but keep in mind that synchronizing large amounts of data is may cause issues on the mobile device.
  • To avoid hitting your email account quota and possible performance issues, archive or back up folders may be set up to store older items. These are normally only saved and accessible from your main computer and will appear as a separate set of folders, but can be moved when needed.

Why isn't Outlook auto-filling an email address in the To field, or using a bad address?
Why did I get a message that an address is invalid, or that no match is found for a recipient?

Outlook has a feature called AutoComplete to automatically store addresses you've previously typed in. It doesn't necessarily sync across different computers, even if you have your CUMC email set up in Outlook on both. If Outlook isn't suggesting someone, you only have to enter it once on that computer/iteration of Outlook for it to save in Auto-Complete.

It may also save bad or old information for a recipient, but you can remove it. Simply begin a new message and start typing the address you want to remove in the To field. When it appears, click the X to its right to delete it (in Web Outlook you may need to use the up or down arrows on your keyboard to highlight the address in the list, then hit the delete key on the keyboard to remove it).

What should I do with spam, junk or phishing messages?

Never reply to or click on links within unsolicited messages, and be sure to review the Email Security page for help identifying and protecting yourself from phishing attempts. To help improve security for everyone you can also Report Unwanted Messages, and use your Blocked Sender list to prevent further attempts from reaching your inbox.

How do I add my CourseWorks Calendar to my email program?

See the CourseWorks Video Tutorials page and select the appropriate link under the Calendar heading.

What happens to my email when I leave CUMC?

Employees will not have access to their email address after employment with CUMC ends due to resignation or termination; the account and messages, etc. contained in it will be deleted. See the Separations and Termination page for more information.

Students who graduate are notified by their School regarding deletion of their 90 days after graduation. The email notifications from the School include information on saving your CUMC email messages, signing up for an alumni account, and other steps that should be taken. If a graduating student joins a department or will be pursuing another course of study at a CUMC School, the department or School must contact CUMC IT within 90 days of the graduation to continue the account without deletion; after 90 days the normal account request procedure should be used.

Students who are studying abroad or on a long absence will not lose their accounts provided their student record remains active in the Student Information System and must verify this with their School in advance.

Why am I getting so many login prompts from Outlook on my computer?

A few issues may cause this. To resolve them please try:
  1. Making sure you are entering your full CUMC email address in any username and email address fields, rather than just your UNI or the older format (mc\uni).
  2. Logging in to Web Outlook to verify you are using the correct password for your CUMC email.
  3. If the wrong password was entered multiple times in a row, see instructions to unlock your account.
  4. If you have access to a shared mailbox or calendar, or are a delegate/have access to help manage someone else's messages or calendar, you will see a prompt for each resource though they shouldn't recur every time you open Outlook. If they seem excessive, continue with the next step.
  5. For Outlook on Macintosh, if you see a message that Outlook was redirected to the server..., check the box next to the Always use my response for this server option, then click the Allow button in the lower right.
  6. For Outlook on Windows or Mac, check for and install updates:
    • Windows - see Microsoft's Install Office updates page for instructions
    • Mac - select Help in Outlook's topmost menu, then Check for Updates and follow prompts.
    For both be sure to check and run updates a few times to ensure that all have been applied, then open or restart Outlook to see if your issues have been resolved.
  7. The email profile in Outlook may have become corrupted. You can try removing it using Microsoft's instructions for Windows or Macintosh, then set it up again using current instructions.

What can I do if my computer or mobile device was already set up for my CUMC email but is no longer connecting?

If you're able to log in to Web Outlook without issue please try Microsoft's Remote Connectivity Analyzer. This provides technical details that IT staff can use when troubleshooting your system or account.
  1. Open a browser and visit
  2. Select the Office 365 tab about halfway down the page, then the Outlook Connectivity option (for issues with Outlook) or Exchange ActiveSync (for problems on a mobile device).
  3. Click Next in the bottom right corner of the page.
  4. Enter your full CUMC email address ( in both the Email Address and Microsoft Account fields.
  5. Enter the password for your CUMC email in both the Password and Confirm Password fields.
  6. If there's an option to Use Autodiscover to detect... make sure it is checked. Do not enter any information for manual server settings.
  7. Check the I understand that I must use... field and type in the verification code.
  8. When verification completes click the Perform Test link in the bottom right corner of the page.
  9. The analyzer may take a few moments to complete and will show Test Details when done. Click the Expand All link in the upper right of the Test Details section, then the Save as HTML icon:
  10. Connectivity Test Results with Save as HTML icon
  11. Follow prompts to save the file to a desired location on your computer, noting where it is saved. You can then attach the file to an email or ticket for your IT staff.

Why am I seeing a Focused Inbox?

This is a feature of Office 365 accounts on some versions of Outlook and Web Outlook. Details are on Microsoft's website including how to turn it off if preferred.

What should I do if my email program is prompting for a Server name or other settings when I try to set it up?

The only information required to set up email in a program or app is your full CUMC email address and password. Other settings should not be entered manually, or there may be issues connecting if aspects of the email system change later on. If you are being prompted for other settings:
  • Make sure you are entering your FULL CUMC email address - - in any username field, and using your CUMC email address password, which may be different than your Columbia UNI password. Log in to Web Outlook to verify it is correct.
  • Check for a Domain field in the program or app settings, and make sure it is blank.
  • Make sure your computer or device has a strong Internet connection. You may want to exit the email program and open a web page to verify the connection.
  • Make sure you are using a compatible email program. Others may not work with CUMC email and are not supported.
  • Check for and install any updates to the email program or app.
  • Restart the computer or mobile device, and make sure it has a strong Internet connection when it starts back up.
If none of the above work, please contact us or your Certified IT Group for further assistance.

Where can I learn more about Office 365 and CUMC email?

If you use Outlook on a computer, information and tutorials on the Outlook on Windows or Outlook on Macintosh still apply. For Web Outlook select the question mark in the upper right after signing in to see or search for help topics, or see the Getting Started in Outlook on the web for Office 365 on Microsoft's website.

The Computer Training page has information on using for free through the Columbia University license. Once you sign, in look for Office 365 or Outlook topics to view video tutorials. The CUMC IT home page and Email at CUMC section of the website will be also updated as new information and features for Office 365 are rolled out.


| TOP |

Last updated 2/21/2018