One of the other volunteers I work uses Thunderbird to send her emails for multiple accounts, and I'm not sure how to fix this problem. I know she has at least two different email accounts set up in her Thunderbird program, one is her personal business account (@domain1.com), and the other is for a charity we both help out with (@domain2.org). Both of the domains have SPF, DKIM, and DMARC set up in the servers that send out the email. I'm not sure how or why this is happening, but when she sends out an email using her @domain2.org email address, it seems to go through the server for @domain1.com. I can see it's doing this, because I've had her send me an email from her @domain2.org account to my personal email (a @gmail.com account), then looked at the header information. The reply to email is for @domain2.org, but the SPF and DKIM info is the IP range and DKIM record of her @domain1.com address. I'm hoping this all makes sense. TL;DR: it looks like even though she can select and send email from either account, it always has the @domain1.com SPF and DKIM info attached. Is this because she imported the accounts into Thunderbird wrong, or something else is going on. I'm not sure who hosts her @domain1.com email, but I know the @domain2.org email is hosted through Google Workspace.