problem with xls attachment

I use the free version eMClient’s.
In the e-mails that have attachments with xls extension I only see the small icon of the program for viewing the images with text “Unnamed attachment”, but not excel file. While trying to save attachment I can only images only but not excel file.
Is there a solution for this problem?

thank you

Can you please send me on of the problematic emails saved as .eml directly at Thank you.