To get to this window follow the instructions in Composing a Message.

To

Enter the primary recipient's email address, or for more than one recipient: several email addresses, separated by semi-colons.

Alternatively you can click on the name To. This allows you to select recipients from your personal address book, or, possibly, from a shared address book.

CC

Enter the email addresses of any recipients you want to receive a copy of the email, separated by semi-colons.

Alternatively you may be able to click on the name CC. If you can do this, then the Address Book window will open.  This allows you to select recipients from your personal address book, or, possibly, from your companies common address book.

Subject

Enter the text for the subject line. This is the title of the email and should reflect the email contents.

Send

Click when you have finished writing your email. This will send your message.

Cancel

Clicking will close the browser window. Any information you have entered in the window will be lost, but you will be asked to confirm this operation.