Regex fields
install Unique Regex Custom field add-on
create a new Custom field type = Regex field
go to Add-ons, Regex > add expression
IP range regex (checks either single or "dash"-separated range syntax, ie, 10.185.20.10 or 10.185.20.10-10.185.20.50) or a comma separated list of IPs
^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$|^.*[-,](([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$
Email check
^[a-zA-Z0-9_.+-]*@[a-zA-Z0-9_.+-]*\.[a-z][a-z][a-z]