The From address can be set at the "List Settings" page of your account.
Under the "List Options" tab, choose "List Settings."
Under the "Basic Information" section, you can click the "Change this address" link.
After clicking the "Change this address" link, a window will pop up where you can choose one of the previously approved addresses you submitted, or use a different address. Choose the radio button for your selection choice and then click "Save Address".
Once you're done, just scroll to the bottom of the page and click "Save Settings." For some guidelines on what address to use please see below.
Use Something Subscribers Recognize
Along with its subject line, your reply address is the first thing your subscribers see of your email messages, so your reply address should be something that your subscribers recognize from wherever they signed up.
For instance, if they did at your website whose address is www.example.com, an address from example.com should be used.
If you are unsure of how to set up such an email address, contact the company that provides you web hosting service for options that are more than likely free or affordable.
Consistency and recognition are very important parts of an email campaign. If they don't recognize the address and name, they will be much less likely to open the message.
Use a Valid Address You Check Regularly
Your subscribers value the personal voice you use in email messages. By using an address you check regularly and encourage feedback or questions, you enhance this benefit.
And because some subscribers will send a message asking to be removed from your campaign, using a valid address is also required by federal law.
We Recommend NOT Using Free Addresses
You can no longer use free email addresses from Yahoo! and AOL as your "From" address. We strongly recommend you do not use any free email addresses for your "From" address at all. Check out the following article for more information on why recommend this and what your alternatives are:
What Should I Use For My From Address?