I have a plain text email containing a URL of the form “http://example.com/path/stra:strb”. Mailspring only automatically hyperlinks it up to and including the second colon (“stra:”), when it should link the entire URL.
I’m guessing this might be special case handling for when people forget spaces after posting URLs, but I doubt that including the :/. makes sense in those cases - the token separator for URLs should just be whitespace or EOF.