Many recipients email program will usually display your
"Mail Account" field information at their FROM field (unless they have set their email program to display all headers).

Note:  Below "General information" picture are from MS Outlook, Outlook Express and can be pulled-up by going to >Tools, >Accounts, >Properties

Remember this, various email programs may call below MS Outlook "Mail Account" by a

different name-- the best solution is that after creating your message, send it back to yourself to ensure that you have selected the correct field and have input the desired text information.

The above "General information" picture are from MS Outlook,
Outlook Express and can be pulled-up by going to...
>Tools, >Accounts, >Properties

The Mail Account field are the information that will appear in your recipient email program "From" field--so enter relevant  info that entice your recipient to read your message.

Note: There are no restrictions on what sort of text information you can enter into the "Mail Account" field, you may use an email address that's different from the "User information" E-mail address: field or Reply address: field

You may even use a different email address at the "Reply address:" field if you want the recipient to reply to that email address instead of the "E-mail address:" that was used to send the message in the first place.

For more info about why your mails get bounced?
See: How Email Works

If you are using your own mail server program...
See: Mail Server FAQs