Multiple users on same SMTP


Hi all

I've searched through the forum search but nothing on the subject. so I ask my question here.
I meet a problem/bug.

I have 1 SMTP server and multiple users.
But I can only put one user per server SMTP.
If I remove the user from the field in the backend of the user, I have a message that tells me "all servers are unavailable at this time"...

How to put multiple users on the same SMTP server?

Thanks in advance
Do you have any hourly quota set for that server (in the server configuration)?
Is "Can send from system server" in /backend/index.php/settings/customers/servers set to YES ?

Keep in mind that a delivery server that is not assigned to a customer, is usable by all customers ;)
My question is similar.
My server reported that there is a limit of 500 emails per hour per hosted domain.
I have 5 domains hosted, so I can send 2,500 emails per hour. So far so good.

My question is:

Can I register 1 sender of each server, and the script does the rotation of the senders (domains)?
Could thus send the same campaign 5 different senders?

Example: every 500 emails sent the script changes the sender, giving me more 500 deliveries ...

Or need to split the campaign into 5 parts and send separated from each?

I hope it was clear.
Sorry for my English.
Thank you.
The only thing you have to do is to make sure you put 500 in each server hourly quota field, then mailwizz will do everything else automatically.