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]