[MissTake]

Not it's not like email for the simple reason that instances can, and often do, block other instances.

When's the last time you heard of Fastmail saying that they were now blocking all emails from Zoho because they didn't like the way a single Zoho user was using Zoho?

Yet this is the sort of thing we see in the Fediverse when one admin takes issue with another admins attitude.

[tovster]

Your analogy happens quite often. Not specifically with Zoho, but if a specific domain is sending spam, your email provider will usually block it at the spam filtering end of it.

[MissTake]

It can, yes, but it's invariably because of a usually valid business decision rather than an admin personal grievience.

I get defederating from known bad actors, but these days it's not uncommon to lose access to an instance because admin don't like other admin policies (ergo some defederation over "The_Donald")

[jfax]

https://en.wikipedia.org/wiki/Spam_Prevention_Early_Warning_...