identity using send-pr with dynamic address

[Hanspeter Roth]

Hello,

I have a system which has a dialup internet connection. That is it
has a different IP address and a different real hostname each time a
connection is established. Since it doesn't need any access from the
internet it only has a local hostname which has no meaning in the
internet.
Using mutt/sendmail I can send mail outbound using an address which
is located on a public server.
Using send-pr I can set a From: field. But sendmail can't forward
the message to an external smarthost since the local
username/hostname seems to be used (in the envelope?).
I only succeeded to send a problem report after setting the hostname
to the current public internet hostname (according the dialup IP
address).
Is there a better way to send prs from system with dynamic IP
address?

-Hanspeter