You're mistaken - it most definitely is listed in URIBL Red: https://multirbl.valli.org/lookup/smtpcorp.com.html On 24/01/2022 17:09, Martin Brampton via Users wrote: > What does this mean? > > URIBL_RED (3.5) [smtpcorp.com:dkim] > > smtpcorp.com is not listed by URIBL Red. Why is this mail being > penalised?