Where to apply for an airport transit visa?

My place of residence My visa application should be submitted to
Iran  Contact the visa section of the Embassy of Switzerland in Tehran  first to explain your request via teh.visa@eda.admin.ch 

Representation agreement

If a State does not have its proper visa section in a country or region, the delivery of a Schengen visa can be delegated to another Schengen State member with an agreement between both countries concerned.

The agreement allows the appointed representation to represent and handle Schengen visa applications within its own competence without consulting the other represented State.

Country / Region Schengen State which represents Switzerland My visa application should be submitted to
Country / Region Schengen State represented by Switzerland