SMTP relay to bridge ancient device with minimal authentication

Our trusty Xerox printer/scanner can no longer send emails, because our ISP has recently tightened access on their SMTP server, requiring “secure TLS”. There’s no newer firmware available for the printer; the best it offers is “SMTP Authentication”, which used to cut it until this change at the ISP.

There are several servers of various OSs running on our network. My hope is that there should be some simple SMTP relay application that I could install on one of these, which can accept email from a trusted machine on the local network (with SMTP authentication), and forward to the ISP with secure TLS.

Googling doesn’t seem to be very helpful in locating such a thing - “SMTP relay” matches a lot of non-helpful pages.

Is anyone aware of a simple solution, ideally for Mac or Linux?

TIA, Ben

Look at Postfix.

Years ago, I was able to fix an issue sending email from a PHP server hosted on Mac OS X Server by adding relayhost = <<hostname with MX record>> to the main.cf file for the included Postfix server (macOS still ships with Postfix).

It sounds like having Postfix listening on port 25 and configured as a relay host would solve your Xerox device’s problem. Even on an internal network, you should probably have firewall rules on the server that rejects port 25 connections unless they come from specific devices that need it.

Thanks Curtis, I’ll try that!

I assume you’ve already looked and failed to find a firmware update from Xerox that might provide the required feature.

Xerox is the worst for updating or keeping anything old. I stopped buying Xerox anythings, when they end-of-lifed my working fax machine, by refusing to sell proprietory toner after only 5 years.

If not Apple, HP for me.

Alas, yes. It’s a big old beast of a workhorse, still working fine, but long past end-of-life as far as Xerox is concerned.