Gmail message garbled on sending

This problem comes up from time to time, but when it does it really annoying.

It’s when I do forward or reply, I can write some text and it’s fine. I can even save the message before sending and it fine.
Everything looks ok but when I click the ‘send’ button, the message then converts to random letters (i.e. garbled) and off it goes.

There is no way to check its all ok other than trying again, so that generally means sending multiple crap forwards.

The google help refers to reading a message that is garbled by changing the encoding, but this is a different problem. I’m the one doing the garbling as I send it.

Any ideas?

Less chardonnay.

From what I can gather, this is most likely a firewall issue.
I’ve emailed you some linkage.