This is probably around forever, but I just spotted it: you can setup one account at Gmail as your master email client for all other email accounts you may have got.

There are two steps that need to be performed:

you need to tell Gmail which email accounts you want to use: 1. in Gmail go to Settings – Accounts ; 2. click Add another email address and fill out the details; 3. click Reply from the same address the message was sent to to ensure Gmail replies with the corresponding address. Step 2. needs to be repeated for any email address you want to use.

you need to verify your ownership of each email address by clicking the verification link Gmail has sent to them; and you need to set up each account to forward all messages to your Gmail account (not every email provider will let you do this, but most do).

Once you’re done you’ll get all the sweetness and benefits of Gmail (search, tagging, spam filtering, …) and still be in control of the addresses you want to use. (You will also be one step closer fulfilling Google’s mission of managing your digital body, of course.)