User validation with LDAP

[Deleted user]

We are requiring to find out if an user is valid/active against LDAP for some of folks like sales/mgmt etc. who need not be having jira access. Since this is not available out-of-box in Jira, our thought is to use a text field

Use case

In Jira screen (e.g. create issue), when reporter enters an email address in a text field

• An behaviour triggers to check if entered email address is ending with some regex pattern (e.g. @[deleted].com), else, show error to enter valid address
• If email address is right, check against Jira user directory, if invalid, show error
• Else, check against LDAP if invalid (inactive/disabled etc), show error

Any thoughts/ideas much appreciated.