about my member of the list

Dear manager,

I am confused as I actually normally joined this list, but it is always
hard for me to post in this mailing list. A friend reminded me that I was
not a member of the list - I do not know the reason. Could you help to
check whether I joined this list successfully.

Second, could I also ask/discuses the general python issues in this
matplotlib? Or any good points if I want to join in a python mail list as

Thanks so much,