Google has announced a change to how Gmail on the web works.

Following our previous notice, we are writing again with an update and the steps we ask you to take if you use Gmail's "Send mail as" feature (sending from another email address).

■ Overview of Changes

Starting in January 2027, restrictions will be placed on the "Add another email address" feature in Web Gmail.

As a result, you will no longer be able to specify and send emails from Web Gmail using non-Gmail (@gmail.com) and non-Google Workspace external email addresses as the sender. 

■ Main Email Addresses Affected

You will no longer be able to send from the following addresses in Gmail on the web:

• Email addresses managed on a department's own mail server
  • Includes addresses managed by the Inbound Email Gateway Service (list of domains in use)
• Email addresses managed by the Email Hosting Service (list of domains in use)

■ Main Email Addresses Not Affected

The following addresses are not affected and can still be used as the sender address in Gmail on the web:

• Secondary group email addresses (@mail2.adm.kyoto-u.ac.jp)
• Departmental email addresses using Google Workspace (kuhp, cseas, etc.), other external email addresses, etc.

■ Future Schedule (Announced by Google)

• Q3 – Q4 2026
  Notifications from Google will appear on the Gmail screens of affected users.
  During this period, sending emails as before will remain possible, but there is a possibility that new external email addresses cannot be added as senders.
• January 2027
  The feature to use external email addresses as the sender will be completely disabled.
   

■ Regarding Future Actions(Updated November 5, 2026)

• Some affected addresses use the Mail Hosting Service (MHS) or the Incoming Mail Gateway Service and are already registered as sender addresses in Gmail on the web in the Faculty and Staff Groupware. We will take steps so that these addresses can continue to be used.
  However, this requires registering the MHS or Incoming Mail Gateway Service domains in the Faculty and Staff Google Workspace. Therefore, the person responsible for each service must submit an application.
  For details, please see the information site:
  https://sites.google.com/kyoto-u.ac.jp/2026sendasthirdparty （japanese only）
• For any other affected address that you want to keep using as a sender, you will no longer be able to send from it in Gmail on the web. Please consider one of the following alternatives:
  • Use an email client (such as Thunderbird or Apple Mail on macOS) and change the sender address with its built-in features.
  • Send email from the web interface or dedicated tools offered by the sender address's provider (such as Outlook or Yahoo!).

■ Detailed Information

For details regarding this specification change, please check the official Google Support page below:

https://support.google.com/mail/answer/17101213?visit_id=639216527491425283-132200507&p=send_as_deprecation&rd=1

We apologize for the inconvenience to those affected and thank you for your understanding and cooperation.