> most of the mail comes down .... it seems to break when transmissions > are over +-600 KB) Try using the TCPMSS target to limit the MSS (Maximum (TCP) Segment Size) value to be at least as small as your path MSS. Hint: iptables -t filter -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu Grant. . . .
