In recent posts by Google and Yahoo new bulk mailer requirements are announced. These requirements go into effect in February and require bulk mailers to implement SPF, DKIM and DMARC if they want their email to be delivered to gmail and yahoo email addresses going forward.
Many Zimbra partners have already implemented DMARC and as such should not be affected by the new policy. If you are interested in learning more about implementing the new requirements check out our SPF, DKIM and DMARC webinar series.
Now we can only hope that Google will implement some restrictions for their own users as well, as it seems most spam going around these days originates from Gmail addresses!