From Amigo

From Amigo is a "From"-address Mail plugin which helps organise the "from-line" when you have multiple accounts. This will save you time and make you look more professional. For example, you may have a work email account setup in OS X Mail. You may also have a personal account setup to email friends, family, etc. It can be embarrassing to email friends from the work account, and you don’t want to email your boss from your personal account! Requires no setup, beyond installation!

Features

• When you send your email From Amigo will check the recipient address with the from address. From Amigo will recommend the best from the address-based accounts you have.
• Allows you to keep track of multiple email addresses. Simply choose which email addresses you would like to use.
• Keeps track of which addresses you send from which account. From Amigo will intelligently suggest an alternative "from" address if it can find a better alternative.
• For both of the above, the BCC lines will be automatically updated so that you have a record of the email address and can save time.
• From Amigo can be set to check for updates automatically.
• Saves you from embarrassing mistakes, making you look more professional.