Re-route is a startup (a scary word these days) that forwards email from your old ISP to your new ISP. This can be done while your old ISP subscription is still valid (we retrieve your email and send it to the new ISP you are transitioning to).

The backend code that processes retrieved email (the address correction, change-of-address notice generation and SMTP communication) was all recently re-done in Tcl (relying heavily upon tcllib's mime and smtp libraries). The Tcl code consists of 3 long running processes (they only go down when we take the whole system down) that handle anywhere between 10,000 -> 20,000 emails per day and sends out double that amount via a local SMTP daemon. The Tcl code uses Berkeley DB persistent/transactional queues for communication and Postgres for updating customer info.

We were going to rewrite the Tcl prototype in C/C++... but why bother? :-)

-- [Todd Coram]


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Cool!  Nice description, Todd.

e-mail remains the original killer app, and Tcl certainly can do e-mail.

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From August 2002 to December 2002 all email destined for myvzw.com was passed through (and routed) by a system primarily implemented in Tcl. News Release: http://news.verizonwireless.com/news/2002/10/pr2002-10-30.html
While the memory of the effort is still fresh in my mind, I collected some thoughts in [myvzw.com and Tcl].