We want to begin collecting customer e-mail addresses from our Web site. Our current file system is mainframe based, storing all data in uppercase format. Are e-mail addresses case sensitive? Do we need to take measures to store this field in an upper/lowercase format or would all uppercase be sufficient?
While there is a strong possibility that your system would work properly if you stored your e-mail addresses in proper case (the first letter of names capitalized), it is possible that there are some older components out on the Internet that are case sensitive. Lowercase letters are usually the accepted form for e-mail addresses.
To maximize your chances that the system will work properly, write e-mail addresses out to HTML pages in all lower case letters.