Scan to email works 1 in 10 times using Gmail

I have two Konica Minolta Bizhub C654e. When we first leased the machines, scan to email worked flawlessly. But, a year later, scan to email only works on a rare occasion. I have not found any rhyme or reason for the issue. The error that reports in the "Details..." is Server Connection Error. Attached is a screen shot of my email TX settings.