need to change the e-mail address on account
We no longer use the atcarpet@froniternet.net e-mail address and need to change the e-mail on this account so that we can send messages using QuickBooks. We can not send invoices via e-mail.
Alla svar (1)
No idea what "account" you might be talking about. Thunderbird is email client software that runs on your computer. You add and delete email account details in that software. It requires no intervention from anyone at Thunderbird.
From the menu bar select File-New-Existing Mail Account or using the AppMenu button click that and select New Message-Existing mail Account. Then enter the details for your new email address.