You must make sure you have POP3 email turned on for the consolidated account.
Microsoft’s new allows you to see email from all your email accounts in one inbox and send messages from other email addresses in one familiar interface.
if you’re tired of checking multiple inboxes, try combining them.
Or you can just start forwarding from this point forward. You should now see your old email address listed on your Gmail page, and it should start checking your mail. Now that your old and new emails are coming to your main account, it’s time to be able to send and reply correctly from your consolidated account. Stay on the Accounts and Import tab in Settings, and make sure you’re still in the account you want to use as your main account. Gmail will now prompt you to send a verification email to the address you just entered.
For the sake of this post we’ll use the Mail Fetcher and import all old emails, too. In the Gmail account you’re using as your main account, click the gear icon in the top right corner and select Settings. Click on the Accounts and Import tab and then click Add a POP3 mail account you own. Enter the email address you wish to bring over to this account and then click Next Step. You’ll be prompted to enter your username and password for the account. Under the Send mail as section, click Add another email address you own. A window will appear asking for your name and email address. This one is a little tricky, but if you want to look like you’re sending from your old account, make sure this box is NOT checked. If you do indeed own this other address, click Send Verification.
The best part is that once you’ve set it up, this takes no management and will run itself.