The "Contact" field contains that information, if I understand you correctly.
But the information is an email address. Many people prefer to keep their
email addresses private (to minimize spam, I suppose) and so that Contact field
is not shown unless you are logged in as a user that has the "e" privilege.

To help prevent exposure of email addresses, SQLite does not store the email
address in the artifacts that comprise the ticket.  Instead, it stores a
SHA1 hash of the email address.  A separate database table (the CONCEALED table)
stores a translation from SHA1 hash back to email address.  The CONCEALED table
is not transferred on a "clone" or "sync".  You can get a copy of the CONCEALED
table by doing:

    fossil config pull email

But that will only work if the person doing the pulling has the "e" privilege
set.