# iptables -t nat -I POSTROUTING -m state --state NEW -p tcp --dport 25 -o eth0 -m statistic --mode nth --every 8 --packet 0 -j SNAT --to-source x.x.x.1
# iptables -t nat -I POSTROUTING -m state --state NEW -p tcp --dport 25 -o eth0 -m statistic --mode nth --every 8 --packet 0 -j SNAT --to-source x.x.x.2
# iptables -t nat -I POSTROUTING -m state --state NEW -p tcp --dport 25 -o eth0 -m statistic --mode nth --every 8 --packet 0 -j SNAT --to-source x.x.x.3
# iptables -t nat -I POSTROUTING -m state --state NEW -p tcp --dport 25 -o eth0 -m statistic --mode nth --every 8 --packet 0 -j SNAT --to-source x.x.x.4
# iptables -t nat -I POSTROUTING -m state --state NEW -p tcp --dport 25 -o eth0 -m statistic --mode nth --every 8 --packet 0 -j SNAT --to-source x.x.x.5
# iptables -t nat -I POSTROUTING -m state --state NEW -p tcp --dport 25 -o eth0 -m statistic --mode nth --every 8 --packet 0 -j SNAT --to-source x.x.x.6
# iptables -t nat -I POSTROUTING -m state --state NEW -p tcp --dport 25 -o eth0 -m statistic --mode nth --every 8 --packet 0 -j SNAT --to-source x.x.x.7
# iptables -t nat -I POSTROUTING -m state --state NEW -p tcp --dport 25 -o eth0 -m statistic --mode nth --every 8 --packet 0 -j SNAT --to-source x.x.x.8