Lots of our customers have questions about that little red open padlock that the desktop Gmail app shows to users who receive mail from senders who do not have opportunistic TLS enabled to encrypt mail over the wire.
The good news is, if your sending platform doesn’t have TLS turned up, there is no impact to deliverability results. The bad news is that your recipients may assume that someone is doing something wrong when they see your message, and may be a bit confused about why the padlock is there at all.
I guest posted on the Salesforce blog once again today, with a very light treatment of the issue and what it may mean for most senders. Any questions? Feel free to post in comments.