Strategies for protecting IMAP (e.g. MFA)
Benny Pedersen
me at junc.eu
Mon Nov 15 03:18:23 UTC 2021
On 2021-11-14 20:26, Matthew Richardson wrote:
> On Sun, 14 Nov 2021 08:12:53 -0800, Michael Peddemors wrote:-
>
>> And there are RBL's now for know IP(s) used by IMAP hackers, including
>> SpamRats RATS-AUTH that can assist in reducing those attacks.
>
> Looking at https://www.spamrats.com/rats-auth.php the "Example Usage in
> Dovecot" says "PLEASE UPDATE".
>
> How would one use a DNSBL like this in Dovecot to reject IMAP
> connections
> from listed IPs?
submission inet n - y - - smtpd
-o smtpd_tls_security_level=encrypt
-o smtpd_sasl_auth_enable=yes
-o smtpd_delay_reject=no
-o { smtpd_client_restrictions = reject_rbl_client
auth.spamrats.com=127.0.0.39, permit }
-o { smtpd_relay_restrictions = permit_mynetworks,
permit_sasl_authenticated, reject }
openRelay, dont do it
resolved version
submission inet n - y - - smtpd
-o smtpd_tls_security_level=encrypt
-o smtpd_sasl_auth_enable=yes
-o smtpd_delay_reject=no
-o { smtpd_relay_restrictions = reject_rbl_client
auth.spamrats.com=127.0.0.39, permit_mynetworks,
permit_sasl_authenticated, reject }
order do matter
for dovecot use allow_nets or weekforce policy server, 3dr party, if
dovecot is the submission it would imho be a winner
i still consider external service as a insecure help
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