The customer declined to move their on-premises installation of QuickBooks Desktop Enterprise to the cloud-hosted Right Networks solution at this time.
It has been determined that the low disk space issue was a transient condition.
It has been determined that the sender's SMTP server likely dropped the connection before AppRiver's SMTP server on the receiving end was able to receive the message. There is nothing further we can do at this point; it is likely that the sender's IT team will need to make changes on their end.
Removed the device that had not been seen in 6 months from our remote management and monitoring service.
The manager has been made an administrator to handle issues in-house.
Removed the decommissioned device from our Remote Monitoring and Management (RMM) service.
The device cannot be patched since it has been offline for a substantial period of time.
Deleted a significant number of very old and unused QuickBooks backup files, freeing up space on the data disk.
It has been determined that AppRiver has recently changed encryption cipher standards, resulting in some senders being unable to connect via SMTP if they were using legacy encryption cipher standards.
Expanded the virtual disk to free up space on the PC, and then utilized PowerShell to switch all OneDrive files to online-only.
Removed the device from our RMM service that had been offline for 6 months.
Granted an AppRiver ETP license to the customer's email alias to ensure email deliverability.
The customer has not replied in over a week; a reboot likely resolved not being able to sign in to OneDrive.
Updated QuickBooks Desktop Enterprise on the client's PC by signing in directly to the admin account.
This issue was resolved by S1 Vigilance.