@jamesinthebox said in Errors on mail setup:
would rather not go through the hassle of recreating the certs
Vivaldi has no exception setting to workaround invalid certificates.
Have you tried to import the certificate
Linux: start certutil and set as trusted:
certutil -d sql:$HOME/.pki/nssdb -A -t "TCu,Cu,Tu" -n "Name of CA certificate" -i filename.pem
Windows: start certmgr.msc and add to store Trusted Root Certificates