I'm calling 'deliver' from Postfix and in some cases from Procmail.

I set this system up more than six months ago and it's been working flawlessly until yesterday (16:52:19 local time) when it, without any apparent reason, just stopped delivering mails!

Lots of checking and googling (I've forgot how exacly I setup the system :), I made 'deliver' SUID and it worked again...

But it seems that all mails that was received between 16:52:19 and 11:07:52 (which was the last mail that couldn't be delivered) is lost!

Is there any way to avoid mails being lost for reasons such as this? Is this a Postfix, Procmail or Dovecot thing?

This system runs on a Ubuntu Intrepid:

Postfix		v2.5.5-1
Procmail	v3.22-16ubuntu3
Dovecot		v1:1.1.4-0ubuntu1.3

Thinking it over again (when double checking this mail), it might have been a automatic "de-SUID thingie or other" in Ubuntu. If memory serves me right, there used to be something like that in Debian long ago... But for whatever reason it DID happen, I'd appreciate an idea on how to avoid loosing mails if something happens to the delivery process...