Стоит Dovecot. Активировал в нем pop3s, пошел в Thunderbird соединяться. Он нашел IMAP 143. Проверил telnet - работает! Самое интересное вот:
iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination
ACCEPT all — anywhere anywhere
REJECT all — anywhere loopback/8 reject-with icmp-port-unreachable
ACCEPT all — anywhere anywhere state RELATED,ESTABLISHED
ACCEPT tcp — anywhere anywhere tcp dpt:www
ACCEPT tcp — anywhere anywhere tcp dpt:81
ACCEPT tcp — anywhere anywhere tcp dpt:https
ACCEPT tcp — anywhere anywhere tcp dpt:smtp
ACCEPT tcp — anywhere anywhere tcp dpt:pop3
ACCEPT tcp — anywhere anywhere state NEW tcp dpt:7602
ACCEPT icmp — anywhere anywhere icmp echo-request
LOG all — anywhere anywhere limit: avg 5/min burst 5 LOG level debug prefix `iptables denied: '
REJECT all — anywhere anywhere reject-with icmp-port-unreachable
Chain FORWARD (policy ACCEPT)
target prot opt source destination
REJECT all — anywhere anywhere reject-with icmp-port-unreachable
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
ACCEPT all — anywhere anywhere
Именно 143 соединяет. 144 нет, 142 нет. Что это за магия?