Hello Alex, the port defined by SMTP standard is 25. See https://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol So this port have to be open on outgoing connections, with the option to have many connections parallel. (Some firewalls could restrict on one connection only, iptables does not limit this, I think).
There is a SSL Port for outgoing SMTP defined, but for using this you need a defined server-to-server connection. This is 465/TCP, but it is normally not used anymore, because SSL is possible by "STARTTLS" on standard SMTP. If your firewall support an SMTP Proxy (with content inspection), you could use this. Iptables does not support this. So: open 25 on outgoing. Best regards Bernd Waibel -----Ursprüngliche Nachricht----- Von: Alex Sviridov [mailto:ooo_satu...@mail.ru.INVALID] Gesendet: Mittwoch, 14. September 2016 14:23 An: server-user@james.apache.org Betreff: Apache james: what output port must be open Hi all I use james on linux and I use iptables to configure both input and output tables. I have no question on input (25,110,143..) however, I couldn't find information what output ports must be open to allow james to connect to other smtp servers. Please, give this information. Best regards, Alex Sviridov
