Sender Policy Framework (SPF) is a standard for authenticating email. It is used by ISPs to ensure that purported senders of email messages are actually the ones presenting the messages they review.
AWeber authenticates using SPF
In order to ensure optimal deliverability of messages, AWeber does authenticate using SPF. While this means that you will most likely not encounter any deliverability issues when using your website's domain in your from address with AWeber (i.e. firstname.lastname@example.org), it is still a good idea to make sure that you've added 'include:send.aweber.com' to your domain's SPF record.
For example, your SPF record might look like this:
"v=spf1 mx include:send.aweber.com -all"
If you're not sure how to edit your domain's SPF records, contact your web host or DNS provider.
For more information on SPF and other standards that affect the deliverability of email messages, review the complete article on email authentication.