Yahoo!:
Through a partnership with SBC, Yahoo! has built a top ranking pay-for dial-up and broadband Internet access ISP in addition to their popular web-based email service.
Yahoo! maintains a top five position for most addresses on business-to-consumer lists. Although Yahoo! does not employ the same drastic filtering measures found at MSN/Hotmail, they do have some content filters in place via their SPAMGuard technology.
SPAMGuard automatically directs messages that are deemed as unsolicited bulk mail to a separate, "bulk mail" folder in the Yahoo! member's mail account. The challenge with the SPAMGuard technology is that it does not return a bounce so there is no way to tell if the mail is delivered into the bulk mail folder or the inbox. It is advised that you test your content using a test list containing at least one test Yahoo! Address. Use this address to check to make sure your message finds its way to the inbox and not the bulk mail folder.
Yahoo! Mail also provides two methods for its members to report SPAM that they receive in their inbox. They can manually report messages as SPAM to Yahoo! Mail without ever opening the message by simply clicking on the "SPAM" button located above the message. This will send the message to their bulk mail folder and send a SPAM report to the Yahoo! postmaster. Another option Yahoo! members have is that they can set up a blocker to match the address or domain of a particular sender. This blocker will prevent delivery of email from that sender.
It has been our experience that Yahoo! also limits accessibility to their mail server by time and quantity of mails but these thresholds are unknown and not published.
As with all ISPs, to improve the chance of messages going to the inbox, instead of the bulk mail folder, it is important to get the subscriber to add your email address to their Yahoo! Address Book. They can do this by opening the message and clicking the "Add to Address Book" link.
For more information on Yahoo!'s anti-bulk mail policies and procedures visit http://antiSPAM.yahoo.com.
