By default, Discourse automatically trims signatures and other “extra” content from incoming emails.
This detection system converts emails to a markdown content that Discourse uses for posts.
However, some site admins prefer this type of content remains for a variety of reasons, so you can enable / disable this feature with the trim incoming emails site setting.
If you disable it; this will disable any automatic trimming of email signatures, and filtering out of additional email content that Discourse does, beyond the main body of incoming emails.
Admin users can also view the trimmed content by selecting 
icon in the upper right of the post.
Once you hit icon, you can see three tabs: Raw, Text, and HTML which shows three versions of the related incoming email.
