With DynamicMailer you can attach any number of files to a message. All files will be encoded as MIME Base 64 files where appropriate (This is the Industry Standard for Binary File Attachments). (this can be any file, but very large attachment files will slow down the sending of the e-mail!).
    To add some file to your message as attachment, click the Attachment button and choose the file from the Add file button dialog.

Attached files frame
    You can simply put the files you want to send here. In the recipient's client they will be seen as usual attachment files. You can manage this files directly within the window in the following ways:
- Click button to add file(s);
- Click button to delete file(s);

ZIP Attach frame
    This frame will appear only after you click on the appropriate  Cilck  Button Show / Hide ZIP attach .Here you can work pretty much similar as described above. All your files would be added into the single archive file named attach.zip.