Example - Mail Flow Logs

When you are trying to find out the reason of some problem - e.g. certain SMTP session is taking too long - it is very helpful to search for the same thread in other kinds of logs.

Example:

SMTP log: 201.63.122.98 [2770] 15:40:58 Start of mail processing

Search for that same thread in Mail Flow logs:

In this case, it does not help too much.

But when searching within Performance logs:

SYSTEM [2770] 15:40:58 SMTP: :25 s. waiting for ThreadLock(3) UserStatisticsUnit_61, waited for 486 instances

This is the reason - the delay is in the User Statistics option (it can be disabled in Status - Account Statistics).