Created attachment 2325 [details] raw-body letter Hello, sorry my bad English. From the beginning of the message there are only dashes, then it is normally visible. I attach a screenshot of the incorrect and correct display and the letter itself.
Created attachment 2326 [details] false decoding
Created attachment 2327 [details] true decoding
Looks like the part which is dashes does not use UTF-8 encoding as declared, but the rest does.
When viewing the message, if you change /View/Decode/Auto-detect to /View/Decode/Quoted-printable you will see the dashs displayed correctly. It /appears/ that the auto-detection of message in encoding is failing in Claws Mail, (but only for the opening section). However, I cannot rule out a problem with the message itself at this point.
Sorry for the tardy response. The problem is caused by invalid UTF-8 in the header of the html attachment: <!--[if !mso]><!--><meta http-equiv="X-UA-Compatible" content="IE�ge" /><!--<![endif]--> <meta name="viewport" content="width�vice-width" />
In fact, I should also have said that the paragraphs which are displayed as underscores/dashes also contain invalid UTF-8, hence the reason that those sections cannot be displayed