An administrator asked if it is possible to limit the number of outgoing Internet emails each user can send each day.
Yes, Exchange 2010 and 2013 can limit the number of messages a user sends, using the RecipientRateLimit and MessageRateLimit parameters in a Throttling Policy. These policies apply to both internal and Internet email.
MessageRateLimit controls the number of messages per minute that can be submitted. When messages are submitted using Outlook or OWA, the messages will stay in the Outbox longer when the user submits messages at a rate greater than the MessageRateLimit parameter. The messages are deferred, not denied, and will eventually be sent.
RecipientRateLimit limits the number of recipients that a user can send to in a 24-hour period. The user will receive an NDR for messages in excess of the limit.
Distribution groups (including dynamic distribution groups) in the Global Address List count as one recipient.
To create a new policy where the users can send to 30 recipients a day and no more than 1 message per minute, you would use this command:
New-ThrottlingPolicy -Name LimitMessagesSent -RecipientRateLimit 30 -MessageRateLimit 1
To assign it to a user, use this command:
Set-Mailbox -Identity user_alias -ThrottlingPolicy LimitMessagesSent
More Information
Understanding Message Throttling
Message rate limits and throttling
New-ThrottlingPolicy
New-ThrottlingPolicy
Do you know of an add-on to Outlook 2019 that will allow me to regulate the number of messages sent on a per minute and/or per hour basis? If I want to email 1400 members of our group but our web host has a 300 emails per hour limit, I have to send in 5 different batches at 5 different times. If I had a way to send only a certain number per minute or per hour then that would eliminate the extra work involved.
Some of the mail merge addins can do this, such as Sperry software's Send Individually. I have a list of mail merge utilities in the Tools section at
Mass Mail Tools for Outlook (slipstick.com)
Thank you!
If you want to to limit the number of external recipients a certain group of people can send to, use “RestrictExtRecips for Outlook” and “RestrictExtRecips for Exchange” tools.
is there a limit on the number of emails a user can receive per minute?
Receive? No, not really... it is controlled in part by the speed of your internet, your mail server and outlook. oh, and message size.
Just as an update, I opened a ticket with microsoft about the messageratelimit we had set to 5 not working, we had recipientratelimit set to 500 so was hard to test, but sending 5 emails was no problem, only issue was the 6th email would go to, Microsoft tech was able to replicate this in their lab with the same issue. Just so happend the next day we had a user do a mail merge and call with a weird error they couldn't send more mail, sure enough it came back and said through some reading of the error couldn't send any more due to a policy set in the system, so the recipient rate limit worked but not the message rate limit, which for our organization was no problem! Just a FYI!
Matt
I have the same problem, as the other ones. I set the MessageRateLimit with the value "2" to a new throttlingpolicy and set the policy to a test user, but i can also send unlimited messages per minute. Also a reboot not solve the problem. The server is a exchange 2013 with cu10. Probably it is a bug in a particular constellation or i don't know.
Hi Sven,
Im also facing this same issue with Exchange 2013 CU10 ? Did you got this resolved? any fix ? Please let me know
Hi Diane,
i am looking for a solution to restrict how users send mass emails on my net work. i use office 360 cloud. the challenge here is that some of the user log in to via webmail client and others through out look .
Thanks
I'm looking for info on the expected send rate for Exchange 2010. We are sending individual 6kb emails to customers, not the same message and not BCC or CC, these are emails with one address going to a specific customer. When we sent the most recent batch of about 900+ emails they went at a rate of 4.4 per second. How fast is reasonable and are there any other adjustments I can make that could lower the send rate to 3.4 a second or even more? I tested my mtu and set it for persistent 1472 as my best also now disabling rss, chimney and autotuninglevel. I also turned off all logging hoping for an additional reduction. netsh interface tcp set global rss=disabled netsh interface tcp set global chimney=disabled netsh interface tcp set global autotuninglevel=disabled My MessageRateLimit is null so this seems to indicate I couldn't send messages any faster yet I've been instructed to create new send policy. If a MessageRateLimit is already set with null how could anything specified here cause an outgoing message to go any faster? After all if there are NO LIMITS anything else using logic would be slower? Creating a new policy and specifying… Read more »
There are a number of factors that can affect it - you can set a throttling policy -
New-ThrottlingPolicy -Name MessageRateLimit -MessageRateLimit 200 -ThrottlingPolicyScope Regular
but it may not help - internet connection speed and server load are a bigger factor. What client is generating the message? Outlook is very slow. It's been awhile since I looked at Exchange 2010, if it uses the IIS SMTP server, the bottleneck could be settings in it.
Diane, thanks for going backwards to 2010! First I'd want to clarify why I'd create a new throttling policy if my existing one can send at an unlimited rate? I've read a few times to just create a new throttling policy but no one explains why a new policy would be faster than the existing unlimited policy.
Seems to me null or unlimited is faster than anything with any numerical value that's been hard coded.
The server has plenty of resources, wen we were sending after I tweaked the network settings the network was only at 10MB on a GB Ethernet and processor and memory at less than 50%
Thanks!
Hello,
This is a great article. I have one question. Would this throttling policy apply to server side rules for a mailbox, i.e (Have server replying using specific template..). What I am asking is what the MessageRateLimit apply to that?
Thank you,
JP
Yes, it would apply to all messages that are sent from the sender's account.
Any way to throttle emails to a certain external domain?
No, not that I am aware of. Sorry.