411 No Such Newsgroup

A 411 ends the attempt to select a group before any article is requested, so nothing downstream in the client is involved. It is also one of the few errors here that can be settled definitively in under a minute, because the server publishes the list of groups it carries and the answer is either in that list or it is not.

Two possibilities, and one lookup settles it

Either the group name is wrong or the server does not carry the group. A LIST against the server, or the group search built into most newsreaders, resolves which. Typos are more common than expected because group names are long, dotted, and often pasted from forum posts where a line wrapped. Singular and plural components are a frequent trap, as are hierarchies that look interchangeable but are not. If the name appears in the server's own list exactly as typed and the command still fails, the group was carried recently and has been dropped, and the list may be cached.

Feeds that omit whole hierarchies

No server carries everything. Text-only and low-tier feeds routinely omit binary hierarchies entirely, so every binary group returns 411 while text groups work normally on the same account. That pattern, all binaries failing and all text succeeding, is diagnostic on its own. Operators also drop defunct groups, groups that carry nothing but spam, and in some jurisdictions specific groups by policy. Two providers can therefore disagree about the existence of the same group with neither of them being wrong.

Group lists carried over from another server

Clients that keep a subscription list survive a change of provider, and the list does not. A reader who switches servers and keeps the old .newsrc or the client's saved subscriptions will see 411 on every group the new server does not carry, all at once, which looks alarming and is not. Refreshing the group list from the new server and resubscribing from that list clears it. The same thing happens when a client is pointed at a backup server in a multi-server setup, since the backup may carry a narrower group set than the primary.

Not the same as an empty group

A group that exists but holds no articles returns a successful reply reporting zero articles, not 411. A client showing an empty group has reached a real group with nothing in it, which is a retention or propagation question rather than a group availability one. Fault for a genuine 411 is split cleanly: a misspelling is local, an uncarried group is the provider's group policy and is not a defect. Neither is fixed by adjusting connections, ports, or credentials, and a reader who has confirmed the spelling against the server's own list has nothing further to change on the client side.