Dr.Monzer Kahf, a prominent economist and counselor states: “There is no difference between Muslims and non-Muslims when it comes to helping in a prohibited transaction. If the transaction is prohibited for us Muslims (example future forex) it is also prohibited to give a product, like training, to those who practice it even if they were not Muslims. Its non-prohibition for them under the Islamic law is not based on a relative concept of morality but rather on respect of individual freedom and a principle that is special to Shari’ah of declining from imposing our values on those who do not believe in our faith. In other word, future forex is as bad for non-Muslims as it is bad for Muslims (so is liquor or tobacco), but out of respect of their freedom and their religion we do not impose our values on them.
The implication of the preceding argument is that helping them in matters that are specific to doing anything that is forbidden in our religion is not permissible also as if it were helping a Muslim committing this same sin.
On the other hand, training and programs that can be used for say either spot forex or future forex are not Haram because then we are talking about a common tool that leaves it to the user to choose its application.
Also offering your mailing list to other organizations is permissible with the consent of addressees, unless it is used to promote a thing that is specifically prohibited in Shari’ah or a thing that can only be used for a prohibited function or transaction. Here again if what is promoted has multiple uses, mixed Haram and Halal, its promotion is not prohibited.