Actually, there are 101 but I have one that is in bouncing status. And this group is one I pay for yearly so don't think that is the problem.
As she has been able to post messages prior to that happening so I'm thinking it is something else altogether going on.
And true all members are allowed to post but in order to join they need to reply to an auto send message I had set up to find out why they wish to join.
As it is set up as a restricted group not that they can just automatically join as it's my way of preventing those that would join to spam the group or
send unsolicited messages, plus to determine which e-mail program they use so that I know how to set them up once I approve their membership.
As it is the group was set up so users that use the same e-mail program the tutorials I write up and keep in the group files can be used and saved into the e-mail program to be shared with other using the same program. where those that use a different e-mail program are not allowed to post as what they share could not be saved/used in the program I and others use if that makes sense and gives you more of an answer.