Mass mail to 20 students - "mails per session limit exceeded"

I created a “mass mailing” to 20 of my students and scheduled it to send at 9:00 am today. I see the following error in my log.

9:00:08 AM [me@mydomain] [SMTP] MailClient.Storage.Application.ItemOperationException:
Cannot send message (Sending email [“Welcome to Class”] - September 12 at 11:00am" failed with error:

‘From’ field address [me@mydomain] not accepted due to the following reason:
“Requested action aborted Mails per session limit exceeded.”
GUIStatus_Exception_Reported = True

Each of the twenty emails was uploaded to the sent folder. I’m guessing that the mails were actually sent, but I’m unsure. Can anyone explain the error and how to eliminate it?

Thanks!

From’ field address [me@mydomain] not accepted due to the following reason:
“Requested action aborted Mails per session limit exceeded.”
GUIStatus_Exception_Reported = True

That sounds like to me your server has a limit on the amount of emails sending at a time or there is currently some server smtp sending limitation problem at the moment as per that error (session limit exceeded). I would contact your server technical support and advise the error.

Sigh. It is definitely not on the SMTP server’s end. The emails have been received by the recipients. Furthermore, the server admins checked the server SMTP logs and saw no errors. Also, I sent another batch of emails through the mail server’s web client, and received no errors. It is definitely an eMclient error.

Oh, I forgot to mention that the SMTP raised my limit to one thousand emails per session. I am sending twenty-five. The limit is almost two orders of magnitude higher than what I’m sending.