Sam Ruby quotes from the new Yahoo! Mail API documentation:
Use WSDL to construct your SOAP client. Even though a service endpoint URL is indicated in the WSDL, you must provide a location URL to your SOAP toolkit. This is necessary to transmit the application ID and the WSSID. In addition, you must set the cookie header containing the cookie that was returned with the WSSID when you credentialed the user in the previous step.
Paul Downey has another quote:
Not all languages that support SOAP are compatible with the Yahoo! Mail Web Service, but all languages that support JSON-RPC are.
First of all, there’s support for the non-SOAP (JSON-RPC) version in more languages, secondly, the way SOAP is used here is so exotic it’s pretty unlikely any client developer will figure out how to use it anyway.
Maybe even more absurd is a fact noted by Dare Obasanjo:
[A]lthough Yahoo! provides SOAP and RESTful JSON web services for accessing one’s mail, I still can’t get POP access to my Yahoo! mail without shelling out $20/year.
OK, I know, I know, company firewalls usually block POP and IMAP traffic. But still, shouldn’t the first protocol used for exposing a mail service actually be a mail protocol?
P.S. I’m continually amazed at the English language’s ability to “verb” nouns. “Credentialed”? Are you kidding?
Stefan, the mail web service is quite a bit richer than what you can get from POP and IMAP. POP is pretty crippled and IMAP is inherently expensive to run, being a stateful protocol. Web services, on the other hand, can be quite lightweight and allow us to add several capabilities that aren’t present in either POP or IMAP (sending, advanced searching, mailbox preference controls, external mail fetching, etc).
Ryan Kennedy Yahoo! Mail Web Service