We have some coding inside of Microsoft Access where we pull data out of a database, create a .pdf and then send to users using Outlook. This works most of the time but probably once a week, the email is generated with the report and then it won't send (we get an undeliverable error):
Your message did not reach some or all of the intended recipients.
Subject: Daily Lab Reports for 6/24/2019
Sent: 6/25/2019 9:12 AM
The following recipient(s) cannot be reached:
QC Database Email Group on 6/25/2019 9:12 AM
This message could not be sent. The client operation failed. Try sending the message again later, or contact your network administrator.
Diagnostic information for administrators:
Error is [0x80004005-0x000004b9-0x00000501].
Submit-Message failed: message id(1), failure enum(6), HResult(0x80004005), EC(0).
This doesn't tell me much so I have no idea why it works most of the time but fails sometimes...
I have no issues sending emails using Outlook (manually) but it just seems to be problematic when something else is kicking off opening Outlook and sending the email. I did turn off the "never warn me about suspicious activity" in the trust center - otherwise, we get the popup every time the task would run to "allow" another application to send email.