I have found that a mailto link which works in Outlook and Thunderbird, does not work in emClient. emClient source says the following for the link which does not render correctly in an email. Also, emClient attaches 3D, which Thunderbird and Outlook don’t. May be the 3D that you attach causes all the problems.
Send Email to appsProcure Support.=0D=0A=0D=0AIf you have any vendor-specific questions, then ple=
ase email using this link to reach out to contact users under you=
r vendor:Send Email to Vendor’s Contact Users