In 7.29

If you have Identd > [x] Use ID from email address set, it works as expected when the server can retrieve your Identd response. If it cannot, whatever appears in the Identd field will be sent to the server as your USER.

This is particularly unnerving if you use /server -m -i when connecting to multiple servers with different identities. For example.

/server Freenode -i Xyzzy Xyzzy- xyzzy Nothing Happens.
/server -m EFnet -i Plugh Plugh- plugh A hollow voice booms.

If EFnet can't reach your Ident Daemon, your WHOIS will look like:

Plugh is ~xyzzy@jargon.net * A hollow voice booms.

when it should look like

Plugh is ~plugh@jargon.net * A hollow voice booms.

- Raccoon

mIRC sends the USER message when it connects to the server, before the identd event is initiated by the server, so the USER message is not related to the identd event. mIRC should use your email address (as a first option - if it is not set, mIRC defaults to your identd userid and if that is not set it uses a default value) in the USER message. The most likely reason it is not working for you is that you only provided a userid in the /server command and not an email address. If you provide an email address, such as "user@address", does that resolve the issue for you?

I'm not sure but it looks like something was overlooked here.
'/server -i [...] email [...]' will actually change the email address field in the option with what was specified, but it won't use that value in the USER message for that connection, this looks incorrect to me because the email address is the first option used for the USER message, I think people, and Raccoon included here, expect the 'email' parameter here to be the ident name used for the connection, it's not about specifying a valid email address.

When you specify an actual email address with /server -i, that is, something with an @ in it, then mIRC does use the part before the @ in the USER command. This particular aspect is rather confusing and has come up on IRC quite a few times. It would indeed be great if it were changed..

Ah ok, but well that particular aspect is fine imo, in this case it actually uses the information you provided, for that connection, it might be confusing to people that it will only use the part before the @, but at least it uses that value provided for the new connection, what do you think needs to change?
For the rest, when no '@' is used, I think mIRC should use that value for the new connection.

When you do put a @ in the email field, mIRC will use it (specifically: the part before the @) for the USER command - this is fine.

When you do not put a @ in the email field, mIRC will not use it (specifically: the entire field) for the USER command - this is confusing.

Raccoon reported the second case, not knowing about the first case, which prompted Khaled to ask whether Raccoon could solve the issue by putting in an @. I think the second case should be changed, so that mIRC uses the email field for USER even if there is no @. I think this is what you are saying as well?

Yes, I was unsure what you meant.

Yeah, fair enough. That's what I get for writing posts before having coffee