Hi, There is too many letters to delivert in our server,although I have set both 'concurrencylocal' and 'concurrencyremote' to 120,It seems too low.And the letter sent to our server will be received at least half an hour later.. :( Can anyone one tell me how can I set the value concurrencylocal&concurrencyremote more high? Btw: It is very strange, Our server will receive about 100000 letters per day, but the benchmark of qmail say it can do it easy... (Our server is Freebsd 3.0 SMP Kenerl+qmail 1.03, 2*PII 400, Intel GX mainboard,3*18G Ibm scsi hardisk,1M ram,there is about 40000 users,i am using assign&cdb instead of /etc/passwd). My english is bad ,sorry. Hotdog [EMAIL PROTECTED]