This is still a problem. Every 3 months I clean 150,000 .hdr files out of my proc folder. I am on SmarterMail Enterprise Edition Version 15.7.6572 with Declude and MessageSniffer
Linda over at Mail'sBestFriend has looked at this a couple of times for me. No resolution, except maybe create a PowerShell script to cleanup .hdr files more than a couple days old and let it run from task manager every night. David and Linda do their best to keep Declude going for us, but it has been dead for a very long time now.
P.S. if anyone needs a Microsoft Word version of the Declude documentation, I have one. PM me for a copy.
John C. Reid / Technology Director
John@prime42.net / (530) 691-0042
1300 West Street, Suite 206, Redding, CA 96001