Yahoo recently made a change to their DMARC (Domain-based Message Authentication, Reporting & Conformance) email policy that could impact nonprofits who send mass emails.
The change will bounce all emails sent from a @yahoo.com email address to another DMARC participant (@yahoo.com, @gmail.com, @aol.com, etc.) if the email is not sent through Yahoo servers (i.e. through donor database software or another email provider).
You can read the full announcement and explanation from Yahoo here.
We recommend that emails sent on behalf of your organization to multiple recipients be sent from an email address that contains your organization’s domain. For example: firstname.lastname@example.org, rather than email@example.com.
If you feel as though this change is affecting your use of Bloomerang, please contact firstname.lastname@example.org.