These instructions apply to the web version of Yahoo Mail in any surfing app and platform.
SelectNew Contactin the left panel.
throw in your Yahoo Mail address in theEmailfield, and then selectSave.
Scroll down toUndisclosed Recipientsand opt for check box beside it.
Alternatively, typeundisclosedinto the search bar that appears to quickly find the entry.
SelectDonein the pop-up window to return to the message.
SelectCC/BCCto the right of theTofield to pop swing open the CC and BCC fields in the email header.
Enter all desired recipients in theBCCfield.
Use anaddress book groupto send messages to multiple people more efficiently.
Compose your message and selectSend.
You will receive a copy of the message, and your address will show up in theTofield.
