“The issue with your situation is not stunnel but the fact that your SMTP client does not have the capability to provide authentication.

As you mentioned, Gmail will require authentication information from the client.

If that information is not provided by the SMTP client application, then the SMTP transaction will fail.

?

I would suggest you consider setting up some kind of SMTP Relay. Which will serve as a proxy between your PLC and Google SMTP servers.

?

You can also take a look at this document and if possible implement the last approach?

http://support.google.com/a/bin/answer.py?hl=en&answer=176600”

Thanks for your help Leandro. Do you have a suggestion for a SMTP Relay?? I have tried Free SMTP Server which was the only thing that has worked so far and  worked almost perfectly except that it can only send out 10 emails a day. And I need more capacity for sending than that.

I also have used trial versions of ArgoSoft, 1^st Mail Server and QK SMTP Server but couldn’t get those to work.

I have tried the Google suggestion for using asmpx.l.google.com but I need to send to vtext.com addresses which are outside of the google domain. I tried adding the vtext.com addresses to googlegroups.com and sending emails using the asmpx.l.google.com server but vtext did not receive the emails for googlegroups.com. So I’m desperate to find some sort of solution.

Thanks,

Stephen Gates

Harold K. Scholz Company

7800 Serum Avenue

Ralston, NE  68127

402-339-7600