We've had a few sporadic reports from users on Webmail, that while composing a new message (or a reply) there is a significant lag between hitting the key and the character appearing on screen.  (intermittent problem, not all the time)  We'd been working under the assumption there might have been an app on their PC/laptop that was pegging the CPU or otherwise heavily consuming resources.

But then it happened to someone on our I.T. team.  The laptop being used had near 0% CPU or disk usage, almost no network activity, speedtest was normal, and while it was happening we checked the server, which was also well within normal limits for CPU, memory, disk I/O, and network utilization.  It was heavily lagging for no apparent reason.

Has anyone else seen or heard of this?  We just got another user complaint this morning about it, and while it was happening, everything on the server looked perfectly normal (and we could not duplicate it on our own PCs).