Output determination through mail

Hi,

I am trying to create output for invoice it have to be sent a PDF file through mail.

I cam across those procedures in Google.

As per that i planned to create mail id in customer master.

As soon i enter the mail id,i get the following error,

Communication error with the external tax system (VERTEX_MS0018)

Message no. TAX_TXJCD864

I am trying this in IDES ,kindly help me what to do.

If i remove mail id and save means,then i could save the customer.

Pradeep