SMTP mail in 3 tier environment

ta5

Hi
We need to send some emails from within a 3 tier environment. Codeunit 400 is a good base I think. Anyway, I have a few question about it:

- Should the email be sent from middle tier or from RTC? As far as I understand, the 2nd parameter in the create-statement is the key to that. Codeunit 400 does not use the 2nd parameter.
- The file "Microsoft.Navision.Mail.tlb" is used as automation object in codeunit 400. Is this file installed by RTC and classic installtion?
- Is "Microsoft.Navision.Mail.tlb" also installed on the middletier?

I will be glad if somebody could share some thoughts, thanks in advance
Thomas