Transitioning Yahoo bound email from Goodmail certification

In early February Yahoo announced they were no longer offering preferred delivery to Goodmail customers. By the end of March, Yahoo will have decommissioned the Goodmail specific mail handling servers. What does this mean for Goodmail customers who have no history of mail to the normal Yahoo mail exchanges? Will they have to go through an IP warmup period?
Thankfully, no, they won’t. IP addresses that have been delivering Goodmail certified mail are being transitioned across to the Yahoo whitelisting program. Just because customers are losing Goodmail certification does not mean they will lose all their sending history at Yahoo. This is very good news, as senders don’t have to give up all their sending history due to Yahoo’s decisions.
I have heard some grumbling from some delivery experts that the ‘pre-warmup’ isn’t meaningful or useful. I strongly disagree. The reason senders have to warm up IP addresses is because spammers are very good at finding unused addresses and exploiting them to send spam. The warmup period gives the receivers a way to evaluate the mailstream from a particular IP and determine if the mail is wanted without having to subject their users to excessive amounts of spam.
In this case, Yahoo knows that good senders will be moving from one set of mail exchangers to another. They have nothing to gain by forcing those senders to go through a warmup period. They know what the mailstreams look like and can special case them. This isn’t a benefit every sender gets, in fact losing established reputation is one of the major considerations when moving IP addresses, ESPs or certification services.
While current Goodmail customers are getting this benefit now, they will be subject to the same spam filtering other senders face at Yahoo. Failure to meet Yahoo’s thresholds for good email may result in loss of whitelisting, bulk foldering of email and rate limiting.
More detailed information about delivering to Yahoo is available on the Word to the Wise Delivery Wiki.