421 4.2.0 sender rejected AUP#SNDR

So I just chatted with a Verizon sales rep. Sounds like if you already have FIOS (which I do), you get $5/line/mo off from whichever plan you select. So if I went with the "Start" plan which includes 5 gigs of mobile hotspot, it would be $55/mo with autopay and paperless billing and FIOS discount. That's the same as the welcome plan just with the hotspot added.  So $110/mo + taxes (compared to $108 with taxes/fees with Sprint/T-Mobile).  They said taxes depend on the state but they suggest expecting 10-15%. The upper end of that range would make my total (2-line) bill $126.50. It's less hotspot data than I currently get, but I'm hoping the calls will be less choppy and that their email-to-text feature actually works - and would experience shorter latency than I was getting with T-Mobile compared to when it *was* working (which could have occasionally been in excess of 24h since this past April).