Clean installation of Deb 8, following howtoforge tutorial - perfect server. Emails have been stucking in mail queue and it seems to be some problem with Amavis. Mailq shows the following: I've enabled amavis log level debug and here is the full output: Any idea what could cause this? Solution for this? Message limit size is set to 0 in main.cf, so as far as I read on the internet - it shouldn't be attachment size related problem.