Why guess...and guess wrong, at that? The information is easy to find.
http://www.religioustolerance.org/zoroastr.htm
Zoroastrians do not generally accept converts. One has to be born into the religion. This belief is disputed by some members.
The traditional wing of Zoroastrianism discourages and does not recognize inter-faith marriages. More details: http://www.religioustolerance.org/ifm_deno.htm#zor.
How is it guessing wrong? From your own words- there is a part of the Z faith that is welcoming to outsiders. There is a (im assuming larger) portion devoted to “keeping it in the family”. Thats like saying you cant be “part german” and be born in the 1930s-40s due to racism.
And words like “generally” aren’t exactly known for being *concrete* in evidence.
No interfaith marriages. Interesting. Especially since my maiden name points to possible Zoroastrian roots and as fascinated as I am by the religion I am not one of them.