432 4.3.2 STOREDRV.ClientSubmit; sender thread limit exceeded?

Question

I tried to an uploaded excel sheet which contains 1000 user records. I tried to sent a temporary password to thew users, in soe cases it succedded and in other cases i I got the error 432 4.3.2 STOREDRV.ClientSubmit; sender thread limit exceeded can you help how to solve this issue.

Solution

there is a limit of up to three concurrent connections for Office365, as stated in this documentation:

New throttling limit for concurrent connections that submit messages

The service has various limits to prevent abuse and to ensure fair use. An additional limit is being added. Under the new limit, up to three concurrent connections are allowed to send email messages at the same time. If an application tries to send more than three messages at the same time by using multiple connections, each connection will receive the following error message:

432 4.3.2 STOREDRV.ClientSubmit; sender thread limit exceeded

Please observe that there are other limits too.

To solve the problem you can:

• Try to send the emails in sequence and give a little bit of time between every item
• Try to use a service that is made for sending a large number of messages, because clearly Office365 is imposing limits to use the service only as a user, not in an automated service.