_WIP_ # Protocol restrictions and IP access Denied access will be shown to the user as failed login attempts. ## Protocol restrictions in Dovecot Protocol restrictions work by filtering the passdb query for IMAP and POP3 as well as reading the JSON value for %s_access where %s reflects the protocol seen by Dovecot. In the future we may use virtual colums in SQL to add an index on these values. ## Protocol restrictions in Postfix Filtering SMTP protocol access works by using a check_sasl_map in the smtpd_recipient_restrictions.