If you have registered a .com/net/org/info/biz or mobi domain name through us (or anyone else for that matter) you will normally get an email once a year asking you to verify your whois details.
This is normal.
If you need to update the details you can do so via your control panel.
At no time do we or eNom (the registrar of record for most of our com/net/org/info/biz domains) ask you to login to anything when you’re checking the data.
So if you do get any emails asking you to login to eNom websites (which we’d never do ..) then please be wary.
Further details of the current phishing (email fraud) emails going around is available over on Domain Name News.
UPDATE:
Enom have provided a screenshot of the phishing email that is doing the rounds (click to enlarge):
NB: THIS IS NOT A LEGITIMATE EMAIL.