ESRS Notification Emails.

We are getting a lot of notification emails recently showing that the ESRS_AGENT file upload is failing and ending the transfer session. Could anybody here help me figure out what this means and how to prevent it? Here is the log file that is attached to the email. We received 26 of them in 5 hours last night.

[2019-01-04 03:24:33] ESRS_AGENT session details...

[2019-01-04 03:24:33] From the device xxxxx with model Number ESRS-VE

[2019-01-04 03:24:33] ESRS_AGENT is copying and uploading file from /opt/esrsve/gateway/work/connecthomeupload/20190104-032159277.eml..

[2019-01-04 03:27:04] ESRS_AGENT file upload of /opt/esrsve/gateway/work/connecthomeupload/20190104-032159277.eml failed.

[2019-01-04 03:27:04] ESRS AGENT transfer session ended.