Hi, Justine. #snac has a feature that is somewhat atypical: the inbox collection, which stores all public inboxes that crosses your instance and send all posts you generate to them, even if no specific accounts on that instance are in the 'to' list. Though it's on specification (what Mastodon calls 'federating' is very similar), some people or admins may find that posts from your instance arrives to them with no apparent reason, and may block due to ignorance and/or overzealous behaviour. You can disable this by setting the disable_inbox_colllection variable to true in you server.json config file.

Also, some people looks at the 0 count of followers / followees and infer (incorrectly) that it's a new account and blindly block your account.

CC: @normis@s.dodies.lv