If the e-mail comes from an unfamiliar source, the recipient is much more likely to delete it. Of course, you still need to optimize the subject line to make sure the e-mail gets opened, but it's the "From" that starts the process.
My most important advice for the “From” line is to be consistent. A consistent “From” line will help your open rate, and prospects will be less likely to report your message as spam. Also, you can ask the prospect to add your “From” address to their address book, a great way to help get to the inbox.
Most companies use the full name of a person, the company name or both. Regardless, I recommend keeping it fewer than 20 characters to help ensure the entire name gets displayed across e-mail clients. If you do use the name of a person, some marketers use a fake name—presumably to help ensure consistency should any employees leave.
Personally, I prefer to use a real person for the “From” line because b-to-b buyers are still people, and people ultimately buy from people. Having e-mails come from a real person helps to build the relationship with the prospect over time. This is especially important for lead-nurturing e-mails.
We personalize the “From” and “Reply to” fields of our e-mails so the messages come from the sales representative that “owns” the particular lead or contact. This helps our e-mails have a more personal touch; and, if a prospect replies to the message, it goes straight to the right sales rep. Most important, it builds the relationship so that when we call a lead (we wait until their lead score shows high engagement), the prospect is much more likely to recognize the sales rep by name and be responsive to the call.