Messages like this are seen:

2015-08-06T16:43:12.533093+01:00 gryphon spamd[17908]: server socket setup failed, retry 1: spamd: could not create IO::Socket::IP socket on [::1]:783: Cannot assign requested address
2015-08-06T16:43:13.534570+01:00 gryphon spamd[17908]: server socket setup failed, retry 2: spamd: could not create IO::Socket::IP socket on [127.0.0.1]:783: Address already in use
2015-08-06T16:43:14.535851+01:00 gryphon spamd[17908]: server socket setup failed, retry 3: spamd: could not create IO::Socket::IP socket on [127.0.0.1]:783: Address already in use
2015-08-06T16:43:15.536638+01:00 gryphon spamd[17908]: server socket setup failed, retry 4: spamd: could not create IO::Socket::IP socket on [127.0.0.1]:783: Address already in use
2015-08-06T16:43:16.538047+01:00 gryphon spamd[17908]: server socket setup failed, retry 5: spamd: could not create IO::Socket::IP socket on [127.0.0.1]:783: Address already in use
2015-08-06T16:43:17.539400+01:00 gryphon spamd[17908]: server socket setup failed, retry 6: spamd: could not create IO::Socket::IP socket on [127.0.0.1]:783: Address already in use
2015-08-06T16:43:18.540714+01:00 gryphon spamd[17908]: server socket setup failed, retry 7: spamd: could not create IO::Socket::IP socket on [127.0.0.1]:783: Address already in use
2015-08-06T16:43:19.542073+01:00 gryphon spamd[17908]: server socket setup failed, retry 8: spamd: could not create IO::Socket::IP socket on [127.0.0.1]:783: Address already in use
2015-08-06T16:43:20.543345+01:00 gryphon spamd[17908]: server socket setup failed, retry 9: spamd: could not create IO::Socket::IP socket on [127.0.0.1]:783: Address already in use
2015-08-06T16:43:21.544702+01:00 gryphon spamd[17908]: spamd: could not create IO::Socket::IP socket on [127.0.0.1]:783: Address already in use
2015-08-06T16:43:21.554501+01:00 gryphon systemd[1]: spamd.service: control process exited, code=exited status=98

With IPv6 disabled, the following is needed in /etc/sysconfig/spamd

SPAMD_ARGS="-d -c -L -4"

(openSUSE Tumbleweed, Augusat 2015)