[Operators] spam resistance

[Philipp Hancke]

On Fri, 24 May 2013, Dave Cridland wrote:
[...]
> I think email was different for three reasons:
> 
> 1) Email came about mostly before the Internet took off - indeed, there's an argument that the Internet expansion was driven by email, not the other way around. This placed restrictions on how email could grow.
> 
> 2) SMTP was chosen as the lowest common denominator; it's a gatewaying protocol at heart (as made obvious when you look at early design MTAs like sendmail). XMPP, however, has end-to-end properties, so it's harder to use for gatewaying to non-XMPP networks together.
> (Though people seem to manage fine)

SMTP is relatively simple and "federated" users look alot like ones in 
your own domain. That is typically different for xmpp, which tends to 
behave less reliable for federated contacts than contacts in your own 
domain.
Another example might be the gtalk chat which hasn't show vcard-temp 
avatars for federated users. Which is kind of interesting because gtalk 
has implemented vcard-temp and vcard-temp update for years.