The feedback feature in Driver Easy is based on Gmail services. If you’re seeing the error message above after you clicked the Submit button in Driver Easy feedback window, it suggests that the feedback message is blocked by Gmail.
To avoid this error message, you should make sure the attachment does not include the following types of files:
.ade, .adp, .apk, .appx, .appxbundle, .bat, .cab, .chm, .cmd, .com, .cpl, .dll, .dmg, .exe, .hta, .ins, .isp, .iso, .jar, .js, .jse, .lib, .lnk, .mde, .msc, .msi, .msix, .msixbundle, .msp, .mst, .nsh, .pif, .scr, .sct, .shb, .sys, .vb, .vbe, .vbs, .vxd, .wsc, .wsf, .wsh
For the detailed information about this issue, please refer to the post: File types blocked in Gmail.