smtpd_sender_restrictions for alias?

[Jonas H.]

I'm using Postfix aliases for a small mailing list. I'd like to make 
sure only a few e-mail addresses can post, so I found this 
smtpd_sender_restrictions thing. However, I couldn't find out if one can 
use that for a single alias? If not, is there any other way to 
accomplish this?

Thanks,
Jonas