Vox technical is hopeless!

My vox acc is 128260. I have had a lantic..net address for 20 years. A few years aho is was moved to Vox. For the last 2 months. my email sending works half the time. I have spent a few hours over at least 7 calls to their technical. I have contacted their sales to get the technical to do something. A month ago I found that my ip address gets blocked. WHY CAN THEY NOT FIX IT? I have too much going on this address, I can't easily change it.