If you prefer to use a Cornell email address instead of a third-party email vendor's sending address, follow the procedure below to establish a Cornell subdomain for sending out email.

A subdomain is an additional section added to a Cornell email domain to identify it, such as “myorg.cornell.edu” or “myorg.mail.cornell.edu”. When a subdomain is created and properly setup through internet identification systems, such as the Domain Name System (DNS), your email will be identified as legitimate by your recipients' email servers.

This setup involves a multi-step procedure, outlined below, and the Email Services team is ready to assist you along the way. 

To begin, you should open a ticket with the Email Services team (see Step 1). IT staff will help you with the process, walking you through all the required steps. In the example below, the email sender will be setting up the domain “blotz.mail.cornell.edu” to use when sending out messages using their EGA address.

1. Contact the Email Services team to begin the process.

2. Decide on a subdomain name to use.
   
   Your options include:
   • Using an existing subdomain.
     If you would like to do this, make sure you get permission from the network administrator for the subdomain. If you are not sure who that is, the Email Services team can help you identify the administrator. (To process email, a CNAME-type domain must be converted to an A-type domain. The Email Services team can assist in that conversion as well.)
   • Use a subdomain of “mail.cornell.edu”.
     Again, the Email Services team will help you set up this type of subdomain.
   • Request a new three-part domain, such as “blotz.cornell.edu”.
     This requires additional steps, which are detailed at Request or Record a Domain Name at Cornell.
3. Set up the subdomain you have chosen in Microsoft 365.  
   Work with the Email Services team, who will provide you with the information needed to do this and assist you with the process.
4. Set up DNS (Domain Name System) records for your chosen subdomain.
   This includes the following records: SPF, DKIM, MX, DMARC, and Autodiscover. (Note that there will be additional required DNS setup in Step 10 below.) Again, Email Services can help with this.
5. Verify the DNS setup.
   After DNS records have been setup, contact Email Services to verify the setup.
6. Create an Exchange Group Account (EGA). 
   This will serve as the mailbox receiving email sent to your new address. This is required to recieve any email replies and bounces.
7. Choose the name for the EGA email address.
   This email address will be the Sender for your newly created domain. This will be the “From” address for messages you send out -- “announce@blotz.mail.cornell.edu”, for example. The part before the “@” can be anything you like.
8. Ask Email Services team to attach this Sender address to your EGA account, so that any email that gets sent to the Sender address is delivered to the EGA mailbox.
9. Work with the third-party email vendor to set up your account so that mailings use the new email address as the “From” address.
   If the vendor's system supports using a “Reply-to” address, that can be any address you like, and can be different from the From address.
10. Follow your vendor's instructions for setting up SPF and DKIM in your account. 
    If the vendor supports DKIM signing of messages, follow their instructions for setting it up. Note that some vendors (for example, Constant Contact) require DKIM setup before letting you use the new “From” address. Email Services can help you with this step.
11. Send a test mailing.
    Contact Email Services if there are deliverability issues with your new EGA Sender address.

To use your new subdomain with another third-party mailing vendor, repeat Steps 7-11.