Sebastian Nielsen via Exim-users <exim-users@???> (Mi 25 Sep 2019 05:49:26 EDT):
> Another way to deal with compromises is to IP-restrict the user accounts so they can only login from where they are supposed to login from.
> If ALL of your users "belong" to the same country - for example i fits a company-internal email server, I would suggest set auth_advertise_hosts to a list of CIDR ranges that your country, or even better, your company, uses.
Maybe we use ratelimit to restrict the numbers of distinct
sender_host_addresses that are allowed to do (successful)
authentication.
The challenge will be to find the right balance between being too sloppy
and too strict.
(Think about a mobile device, reconnecting serveral times over the
course of a day)
Best regards from Atlanta/GA
Viele Grüße aus Atlanta/USA
Heiko Schlittermann
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