'git format-patch' on older commits, and mailinglist

Hi,

Recently, I sent out patches which were fixed up with --amend on older 
commits. When I sent them out, the patches contained
     Date: <more than 2 days old datestamp>
in the headers. Now, sending these mails is fine, and mail clients 
generally handles it perfectly fine. However, after doing this I got 
an email from postmaster@vger.kernel.org, basically telling me to not 
do this, since they get a lot of bounces where the return is marked with
     Diagnostic Code: smtp; 550 (4.5 DATE_IN_PAST_48_96 Date: is 48 to 
96 hours before Received: date)

This is understandable. The question is, do we fix the tools to handle this, so that emails are always generated with now() date, and the commit content contains a tag for the original commit; or do we simply say, always send patches to the mailing list with a current timestamp?

Maybe my workflow is incorrect too. I don't mind pointers on this.

I guess rebasing before generating the patch series would have fixed this, but I really didn't need to. I simply reset HEAD~2, fixed with --amend, then cherry-picked the other on top again; then created the patch series.