mail sending limits


May 22, 2020
What parameters do i set and where if
i need to send 4 emails per minute per smtp node
so hourly i would be able to send 240 Emails per smtp node
however i would not want to send one lot of 240 email at one go,
instead distribute sending for the whole hour to 240 total

Please advise correct settings or is this something in the manuals i am missing ?
Thank you in advance,


Staff member
Apr 9, 2019
You cant control the speed based on the Sending Node but you can control the cumulative speed of all sending nodes involved in sending a campaign.

In Mumara Campaigns, you can control the speed

- Based on Individual Campaign
- Based on User Limits for the selected package
- Based on the value defined in Application Settings

So in your case, you can use a single sending node per scheduled campaign and apply custom hourly speed for accurate results. or if you are using multiple sending nodes for a single campaign, then multiply the hourly speed accordingly e.g. if you are using 10 sending nodes per campaign and you want Mumara not to send more than 240 emails per node, then the custom hourly speed of the campaign should be 240x10=2400 and Mumara will try to distribute equally among all sending nodes (unless the calculations are disturbed by the batch size set in Application Settings). If you are sending a small campaign but has a bigger batch size set and use more than 1 thread, it can up/down the calculations accordingly.

For example:

Case 1:
If your batch size is set to 500 and you are using 1 thread for a 500 contacts campaign. In this case, Mumara will open a socket connection with your first sending node and make a batch of 500 emails and dispatch it. Now it will switch to sending node 2 and try to make the next batch but when it doesn't find any contacts for the next batch, your campaign will be finished and the end result will let you know that just 1 of the sending nodes was used.

Case 2: If your batch size is set to 100 and you are using 1 thread for a 500 contacts campaign. In this case, Mumara will use 5 sending nodes to send out 500 emails before the campaign is finished.

Case 3: If the number of contacts involved in a campaign is greater than the (nodes x batch size). Let's support you have a campaign of 5000 contacts and sending over single thread and 10 sending nodes. This way every sending node will send a batch of 100 emails and move to the next sending node. So, all of the 10 sending nodes will be sending ~500 emails each (probably).

Note: Keeping in view the fast selection, we have set the random selection of Sending Node as the default option while scheduling a campaign. If you want the contacts to be equally distributed over the sending nodes, you can select the option "Sequential Selection" while scheduling the campaign.