Question

I’m using Blackberry’s ESS that includes support for sending an email to its own SMTP server which then pushes the email to the Blackberry device.

When using Thunderbird to send to this SMTP server, it works perfectly, I can send multiple emails without problems.

However, when using SmptClient, or a few third party componenets, and finally my own custom class, the email sends just fine, but on sending QUIT the ESS’ SMTP server seems to crash and subsequent attempts to communicate with it timeout.

I’d like to place a proxy of some sort between Thunderbird and ESS’ SMTP server to monitor the commands Thunderbird sends and how it handles the connection to the server.

I could build something myself, listening on a local port and pointing Thunderbird to that port, but I figured someone on SO might’ve used something similar in the past.

Does anyone know of an existing app that would achieve this, or a different approach I could take?

The issue is consistent. Thunderbird consistently works and my own attempts consistently fail, so I feel confident it’s something these .NET components aren’t doing that Thunderbird is. I should point out that ESS’ SMTP server isn’t exactly well-written, it seems to return incorrect status codes to some commands (pretty much 250 in response to everything) but because it works perfectly with Thunderbird, I’m confident there must be a way to get it to work from within .NET.

Answer 1

A quick Google reveals SMTP proxy.

SMTP Proxy server is a very useful
utility if you are trying to debug
problems with your email server.

It looks quite powerful, and useful for your requirements.