email from router to OBSD workstation on LAN

[shep]

My ISP is starting to charge if Bandwidth quota is exceeded and I would like to be able to monitor WAN bandwidth. Something on the order of vnstat as used in this BSDnow OpenBSD router tutorial.

I search for and purchased a refurbished router that is supported by OpenWRT.
OpenWRT allows for the creation of router firmware with custom apps. vnstat is one of those apps along with several email options.

I would like to send a monthly email with the wlan stats to my main workstation and avoid the use of OpenSSL libaries. Flash memory space is at a premium.

The default opensmtpd is configured for localhost email. I could not find any examples with router emails to opensmtpd. Most examples for router generated email use an external mail server and mine prefers ssl/tls.

I'm thinking that I should be able to set up a simple *-nossl/smarthost email program in the router, with an alias in the routers /etc/hosts and send to my main workstation, port 25, on the LAN. In the above link there are several email programs. I'm looking for comments as far as security and the viability of the idea.

As an aside, the OpenWRT project looks to be kinda of neat. I can imaging setting up secure router access with my own self-signed certificates.

[jggimi]

You can configure your smptd.conf accept filter rules in many ways, such as by incoming IP address. or Email address. This is done with accept from source <table> or accept from sender <table>. Perhaps one of these two options will help?

Keep in mind, in smtpd, the first matching rule wins.

FWIW, I use netflow statistics collection on my routers, consolidating the results from all onto one of them for reporting or analysis.