.TH dns_mx 3
.SH NAME
dns_mx \- look up Mail eXchanger
.SH SYNTAX
.B #include <libowfat/dns.h>

int \fBdns_mx\fP(stralloc* \fIout\fR,stralloc* \fIfqdn\fR);
.SH DESCRIPTION
dns_mx looks up MX records for the fully-qualified domain name in
\fIfqdn\fR. It puts the MX records into \fIout\fR and returns 0. Each MX
record is a two-byte MX distance (big endian) followed by a
\\0-terminated dot-encoded domain name. If the domain does not exist in
DNS, or has no MX records, \fIout\fR will be empty.

If dns_mx has trouble with the DNS lookup or runs out of memory, it returns
-1, setting errno appropriately. It may or may not change \fIout\fR.
.SH "SEE ALSO"
dns_mx_packet(3), dns_ip4(3), dns_ip6(3)