Exchange 2019 large distribution group - Disk Queue Length slows mail server

Copper Contributor

We have 2 * Exchange 2019 servers running in a DAG with approx 11,000+ users.  To send out urgent notifications we have a Distribution group with all users that we send out to.  We do not want a 3rd party company.  There are several departments that use this DL too that have the autority.  Our organisation is linked with 2 other organisations each with their own DAG but 1 AD/Exchange environment.

When we send out to this DL, there is a lag in users' Outlook experience and we notice the Disk Queue Latency jumps up to around 5-10 for about 5 minutes and we can see the message queue has up to around 100 messages per DB.

What I am look for is a way to Throttle either the sending mailbox (in messages per minute and not per day such as the recipientratelimit setting) or the 20 mailbox databases from accepting such a large burst.  Exchange databases are spread over 2 drives with separate log drives.  Mailbox totals are around 13TB.

2 Replies
Just bumping this, has anyone got a solution here? We've now added another 500 staff members to our DL and this morning I've see the disk queue latency jump up to 50.
As far as I'm aware there is nothing available to throttle at that level. It sounds more like the underlying infrastructure is not sized correctly for your message profile. Maybe more mailbox DB's with fewer mailboxes on them on separate storage so that's not a bottle neck