E-mail addresses case sensitive?

[obj]

I was always under the impression that e-mail addresses are not case sensitive. However, after experimenting with one e-mail address it seems that it is, at least on my Windows server. I can send e-mails with upper/lower case mismatch but cannot receive e-mails. Any thoughts?

[dpyers]

Actually, everything to the left of the @ sign is supposed to be case sensitive and everything to the right is supposed to be case insensitive. The left side is also supposed to allow about 10 or 12 special characters - e.g. %, #, *, etc.

However, email servers typically allow the administrator to toggle case sensitivity and many will have the special characters turned off as well.

[obj]

Hmmm, that is interesting. What surprised me completely is that she could send e-mails with mismatch case but not receive. Wouldn't you think that it applies to both, send and receive?

[dpyers]

It all depends upon what the receiving email server is set up to handle. Sending email involves little or no address checking beyond simple format syntax. It doesn't get into the content of the address field.

Most email servers are set up to allow case insensitivity on incoming mail.