Luc,

I never used salesforce but I’ve connected to other websites. I recommend that you use the developer mode of your browser, record activity, log in to your account and then look at the post that was created. From this you can construct the proper url in mathematica.

For example in safari you can right click on the line and have it give you the curl form which is everything you need to make it in MMA. The same holds true of all the other website interactions (often “post” or “get” urls)

If you have trouble, post the curl you are trying to form and I may be able to help you construct it in mma.

I hope this helps.

Regards

Neil