How to check if mail is received or sent in the old format

Here is an example of how to use Gmail (Keio Mail's webmail)

1. Log in to Keio Mail.
   
2. In the “Search” field, enter to:“(your old style address)” e.g.: to: “keiotaro@a2.keio.jp”. The old style mail you received will be displayed in the search results.
   
   
   
3. In the “Search” field, enter from:“(your old style address)” e.g.: from: “keiotaro@a2.keio.jp”. The old style mail will be displayed in the search results.