Donors must provide a valid email address when donating via your Fundraise Up donation checkout. These are validated by ZeroBounce in order to ensure high deliverability for receipts and transactional email.
All public Fundraise Up donation checkouts require email to ensure that communication with the donor is possible regarding their transaction. During Fundraise Up checkout, email addresses are validated by one of our technical partners, ZeroBounce.
It's vital for organizational health to ensure that the email addresses on any mailing lists have high deliverability, so that emails from your organizational addresses aren't deprioritized or marked as spam by email providers. This also applies to Fundraise Up transactional emails that are not marked with a custom From address, as we additionally need to make sure that our stock email delivery addresses remain high-priority with email providers.
We have a limited ability to whitelist rejected emails, and the ability to review cases with ZeroBounce to ensure that emails returning as invalid. Please contact support if you get reports of any emails being rejected that seem to correspond to valid email addresses used elsewhere.