The following is is a posting from the Official Gmail News Blog:

Posted by Joyce Sohn, Product Marketing Manager

It’s that time of year when students are graduating, and in many cases getting yet another email address to check — an alumni account — as a graduation present.

Whether you have an alumni address, a work account, or your own domain that you like to use, rather than logging in and out of multiple accounts, you can set yourself up so all your mail ends up in your Gmail inbox. And you can send mail from any of the other addresses you own right from Gmail as well.

There are two steps to make this happen:

1. Set up mail forwarding or fetching
Many email providers offer free auto-forwarding to other accounts. Log into your non-Gmail account and set your Gmail address as the forwarding target. If your other account doesn’t offer forwarding but supports POP3 access, you can use Mail Fetcher in Gmail to automatically check your other account for new mail and download it to Gmail.

2. Set up custom “From:”
Gmail’s custom “From:” feature lets you send mail with one of your other email addresses listed as the sender in place of your Gmail address. There’s a good step-by-step for how to set this up in the Help Center, but the basics are adding the address you want to use and then verifying that it belongs to you. Once you have your custom “From:” set up, you can pick which address you want to reply from in the “From:” address drop down while composing messages.

P.S. If you’re a recent grad and want more tips on how to use Google during this transition period, check out the Google for Students Blog, where we’ll be posting more tips like this weekly for the next couple months.

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Tip: Check and reply from multiple email addresses in Gmail