I have an email integration that receives messages (from Snowflake) that are formatted for human consumption using HTML. Part of the message is a link labelled 'LOG IN' with an URL that contains the Snowflake account name. The integration uses message.extract to include the account name in the alert message.

This used to work fine until Snowflake released a version where an image was added to the email messages.
After playing a bit with sending manually edited email messages, I found that links were suppressed from the alert description if I added a small image to the message. (The links are still present in the attached Body.html file.) The alert description is specified as {{message}} in this case.
Why aren't the links included in the incoming message field when the email contains an image?
The below screenshots shows results when sending an email without image, and then the same email with a small image added.

