If the email accounts are from different email providers then you can open all mailboxes at the same time, each in a separate browser tab as shown in the screen shot below: If you have multiple accounts from the same provider i.e.
You may want to combine the Outlook Inbox of different accounts, into a single file, if you want to arrange the email accounts in your Outlook.
When you combine Outlook inbox, you also save on-screen space.
If you use the automatic method to create email accounts in Outlook 2007 and later versions, by default, each email account will prompt Outlook to create a new file and hence, a different inbox. In the File menu, click on Account Settings and in the drop down menu that appears, select Settings again. You will be presented with the Account Settings window that lists all of your existing email accounts. Click on the email account whose inbox you wish to combine.
If the label consists of multiple words, separate the words with a hyphen.
Click the blue magnifying glass icon to execute the search. Click the drop-down box with the empty check box icon and click "All." If you see the link that reads "Select all conversations that match this search" above the selected emails, click the link as well. Click the "Labels" button and type in the name of the new label you want to assign to all the selected emails.
By this, you can check all your emails from one place.
You might also need to access your email from different locations and on several devices.Joe could decide to keep his email accounts separate.To do this he could simply access each mailbox separately by using Web mail to login to each account.At present, Gmail doesn't provide an option that lets you quickly combine two different labels into a single label.However, Gmail has a special search feature that lets you display messages that belong to certain labels.