We are using Mailman 2.1.13 from Debian repositories (which is the latest version for squeeze). We are facing late mail delivery problems and after some research, we think we managed to overcome these problems by changing some configuration options. Although Mailman seems to running fine, we have observed an issue.
The issue is related with IncomingRunner. This qrunner process takes up approx. 1 GB RAM and sometimes causes high loads. We couldn't determine what causes high RAM and CPU usages.
The question is; this is an expected result of Mailman process? If not, how can we determine the root cause of this problem?