The EcoStruxure IT Gateway gathers the event.txt log daily for most APC devices using the Gateway's FTP credentials, apc/apc by default. If the Gateway credentials don't match those on the device, a warning email message is sent every day for each device: Warning: System detected an unauthorized user attempting to access the FTP interface from <IP address>.
Change the FTP settings in the Device File Transfer Settings option in the Gateway to match those on the device. See Configuring device file transfer settings.
Note: SCP is supported in Gateway 1.9.0 and newer. SCP is a secure alternative to FTP for event.txt, device configuration, and firmware update. It is strongly recommended that you use SCP and disable FTP on your APC NMC-based devices.