Scan to Email Failing with Consecutive Print Jobs

[Woliwon]

The device is probably using an smtp relay server over port 25 without authentication or encryption. The printer doesn't actually *send* the email.. it goes to the smtp server it's pointed to over the port its told to use and uses encryption and authentication if told to do so and required. It's probably something on the mail server side. You could tray setting the device up with it's own gmail account? Not likely to have that issue using gmail. 

[Bryansol13]

We have an Altalink C8045 that generates an error message when using the scan to email function and scanning consecutive jobs in short duration. Usually the error message pops up on the 4th job saying "Job deleted. No messages were sent. One of more of the email addresses are invalid. Check your recipient addresses, remove invalid addresses and resend."
The recipient email is valid as the first three scans are received. The error message then stays in place for about 24 hours.

What is causing this issue?