serialmail

serialmail is discussed on the serialmail mailing list.

The latest published serialmail package is serialmail-0.75.tar.gz.

What is it?

serialmail is a collection of tools for passing mail across serial links. It works with qmail: you use qmail to deliver messages to a maildir, and then serialmail to deliver messages out of the maildir.

serialmail is designed to handle three common types of mail delivery between a dialup computer and an ISP:

Delivery to the ISP. The dialup computer sends all outgoing mail to the ISP.
AutoTURN delivery from the ISP. After the dialup computer makes an SMTP connection to the ISP, it automatically receives an SMTP connection back from the ISP if there is any new mail for it. This provides the same power as ETRN but does not require a special client.
User-controlled delivery from the ISP. A user with a shell account can switch from qmail-pop3d to serialmail without pestering the sysadmin. The user can also decide whether undeliverable messages should be left for POP retrieval or bounced back to the sender.

serialmail supports SMTP, including ESMTP PIPELINING, and QMTP.

serialmail uses ucspi-tcp/tcpclient for networking. It can also be used with future UCSPI clients for transparent compression, IPv6, etc.