EWS - office 365 via proxy

Hi,

We are migrating our mailbox to office365.
The customer requirement are to :
- use the Exchange Web Service soap (so no IMAP/POP3) to access the mailbox,
- read mails and attachement,
- and use a proxy to access the office365 mailbox.

So we tried several solutions with, each time, the proxy configured in the Appian administration console :
- First, we used the Advanced Call Web Service (SOAP) plugin but the call to the web service ended with a "TimeOut" error.
We think that this plugin is not use the proxy configured in the administration console,isn´tit?
- Then we tried the getEWSEmails () function of the Exchange Web Service plugin but we also got a "TimeOut" error. We think that this plugin is not use the proxy configured in the administration console,isn´tit?
-Then we tried the smart service Call Web Service as according to the Proxy section of the Administration Console this smart node used the configured proxy.
However, after filling in the URL of the WSDL and the authentication informations, we are unable to get the services with the associated button.
The error message received is: "The WSDL can not be processed because the client and server failed to negotiate SSL security. (APNX-1-4045-004) »
- Finally, we created a REST integration object with a POST method in which we send a SOAP request to the body.

This last solution works but does not allow us to handle attachment without to use pv on a process like the Advanced Call Webservice plugin can do.

So could you answer us regarding these questions:
- What are your recommendations regarding our requirements ?
- Why the smart node Call Web Service does not work with the proxy configured ?
- Do you know a solution to directly convert a Base64 encoded text field (mail attachments) to a document in Appian ?

Thank you in advance for your answer.

Alexis