send email with base64 encoded attachment

Hi,

i have to send encrypted and signed edifact mails with an base64 encoded attachment. Encryption and signing is working fine.

Now someone wrote me, that the attachment is not base64 encoded.

I use the chilkat.dll with powershell and add 1 attachment to every mail with: "$contentType = $email.AddFileAttachment($pathname)"

Is there a way to add the attachment as an base64 part ?

Regards Frank