1 .\"	$OpenBSD$
2 .\"
3 .\" Copyright (c) 2019 Martijn van Duren <martijn@openbsd.org>
4 .\"
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17 .Dd $Mdocdate$
18 .Dt FILTER-DNSBL 8
19 .Os
20 .Sh NAME
21 .Nm filter-dnsbl
22 .Nd block senders based on dnsbl
23 .Sh SYNOPSIS
24 .Nm
25 .Op Fl mv
26 .Ar blacklist
27 .Ar ...
28 .Sh DESCRIPTION
29 .Nm
30 looks up the IP address of the sender at the
31 .Ar blacklist
32 .Pq a domain name
33 and by default drops the connection if it is found.
34 If the
35 .Fl m
36 flag is specified it will allow the message to continue, but it will be marked
37 with an X-Spam and X-Spam-DNSBL header.
38 For more verbose logging the
39 .Fl v
40 flag can be used.
41 .Pp
42 Lists matching the IP address are echoed back to the sender.
43 Paid services from Abusix and Spamhaus have their key stripped.
44 .Sh SEE ALSO
45 .Xr smtpd 8