Other e-mail client attachments do not open via eM

Why can’t I open attachments of e-mails that are saved in computer through other e-mail clients, e.g. Outlook? eM opens e-mail then the attachment in it has the same logo as eM (not word or excel or pdf etc logo) and when I double click to attachment, eM opens the same e-mail again (trough the attachment). So when I’m finished, I’m with two e-mails containing attachments.

Could you please send me one of the attachments at wilson@emclient.com so I can test it? Thank you.