Gmail allows you to automatically forward incoming emails to the other email address, but unfortunately, it is limited to only one address at a time in Mail Settings.
However, a trick on the filtering feature in Gmail can be applied to automatically forward incoming emails to multiple recipients at once. Here’s how:
1. Go to Mail Settings > Forwarding and POP/IMAP > Forwarding. Click Add a forwarding address button to add an email address that you want to forward the incoming mails.
2. The inbox of that email address should have an incoming mail from Gmail Team, asking for permission to allow the forwarding. Approve for the permission so that the email address is selectable for forwarding address in Gmail.
3. Repeat Step 1 and Step 2 for the other email addresses. Note that there will be a limitation of 20 email addresses that can be used for forwarding using this tricks, but it should be adequate for normal use.
4. To configure the first forwarding, go to Mail Settings > Forwarding and POP/IMAP > Forwarding. Click on the radio button Forward a copy of incoming mail to, then select one of the email addresses that you wish to forward. Then click Save Changes button.
5. For the other email addresses, a filter is required to be created, so that the incoming emails can be forwarded to those addresses. Go to Mail Settings > Filters > Create a New Filter.
6. Put a asterisk (*) at the To field, then click Create filter with this search.
7. Check the checkbox for Forward it to:, then select the other email address from the list.
8. Click Create Filter button and you are done! Simply repeat Step 5 to Step 8 for the rest of the email addresses, and now whenever there is a new incoming mail, it will be forwarded to all of the email address that you have configured. Congratulation!