How To Speed Up Local Delivery
Problem reported by Scott Forsythe - August 11, 2015 at 12:48 PM
Today our spool got backed up. The status for most of the messages was "Local Delivery". Our server had plenty of memory and CPU available but during the peak time of the day SmarterMail could not deliver fast enough. We did not have any attacks, spammers, etc. during this period. Our users had ~1hr delivery delay.
Does anyone have any tips to isolate what is causing the delivery problem? During the spool backup the messages seem to process periodically and it appears that they are stuck in a process.
Scott F.

3 Replies

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Employee Replied
August 11, 2015 at 1:39 PM
Employee Post
Hi Scott,
If you are having long delivery time it may be due to your disk IO.  The next time you see this run perfmon on your hard drive(s) and look at the following value.
Highlight the following:

% Disk Read

% Disk Write

% Disk Idle

% Disk Time

Current Disk Queue Length

The purpose of each of these counters are:

% Disk Read – How much time your Disks are being read

% Disk Write – How much time your Disks are being written to

% Disk Idle – How much time your Disks are idle (not performing any action)

% Disk Time – How much time your Disks are in use

Current Disk Queue Length – How long the Operating System must wait to access the disks

The values you want to see are:

% Disk Read – Less than 15-20%

% Disk Write – Less than 15-20%

% Disk Idle – Over 85%

% Disk Time – Less than 15-20%

Current Disk Queue Length – Less than 1
kevind Replied
August 11, 2015 at 2:59 PM
Brian, excellent reply -- not only did you explain the counters, but provided optimal values.
Follow-up question: Does it still make sense to put the spool and mailboxes on separate drives as recommended in this post from a couple years ago?
I'm familiar with another mail server that 'moves' messages from spool to mailbox. It's more efficient to keep them on the same drive as it's a simple file rename.  But I think SmarterMail actually re-writes the message into the mailbox so separate drives would be best.  Let us know.
Employee Replied
August 11, 2015 at 3:10 PM
Employee Post
Hi Kevin,
Yes for high volume servers it would be best to have your spool and data on two different drives.  The blog post is still valid in the recommendations. 

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