Sometimes after several emails are sent the application will fail to send. Could you tell me specifically this error if you don’t have a full list to send me?

This looks like your email server (SMTP server) is not accepting new emails.

Many email servers have limit on how many emails you can send for a certain time period. If the email sends too fast, the new ones might be rejected or marked as spam. If this is the case, you need to slow down the sending process (under Broadcast > Options).

The error code or description is from the email server. Broadcast By Email simply captures it and presents it in the status column. If you switch to a different SMTP server, the error message might be very different. So the best place to check error code is the SMTF server manual.

Does the software support multiple outgoing email accounts sending at same time? Also what is the realistic number of emails/hour that is will send under average conditions (average desktop). I am looking for software to allow me to email out 1million/24 hours to opt-in lists. Although I can run multiple versions of the same software if necessary.

No, the software currently only supports one outgoing email account, ie, one SMTP server.

The speed of sending out an email largely depends on your server. It is not dependent on the email client software (Broadcast By Email). Usually, commercial email servers control the amount of emails it can receive from email client. Broadcast By Email does have control to slow down sending emails, in order not to flood your email server and your emails being marked as spam. We do not know the exact connection speed you have, but normally, you can send one email a second.

To send 1 million email per day, you need to send about 12 emails per second. So you definitely need multiple email servers and use multiple Broadcast By email software.