You can include a custom excerpt of an e-mail by putting it between :excerptstart and :excerptend
:excerptstart This is my excerpt text. :excerptend This is the main body of my post.
Images in excerpts
It is possible to include images in the excerpt even if you are using plain text emails. Wherever you want the first image insert the text “#eming1#” the second image “#eming2#” and so on. The images are numbered in the order they were attached to the email.
:excerptstart This is my excerpt text. An image will go here #eming1# :excerptend This is the main body of my post.