It started with somebody saying they didn’t get my e-mail message. Weird, but the Internet isn’t perfect. Resent; problem solved.
But then it started happening more often. It was still only to one client of mine, though, so I passed it off as some weird incompatibility between their servers and my servers. It was annoying and something I intended to look into but it was easy enough to check via IM and confirm e-mail receipt when I didn’t hear back with an e-mail reply right away. And I was starting to be able to track that it really was only messages I would send, not ones I was expecting to receive.
Then in late October, the problem got bad enough that I was not receiving about 1 in every 5 e-mail messages sent. At least, that’s as far as I know because over the course of a couple of days I was told that how many messages needed to be resent. And confirmed that the sender wasn’t getting any notification of any problem. So on October 22 2015 I sent in a request to my ISP, Arvixe, to have them look into it. In the past, they had been pretty responsive to such things. Not so this time.