Describe the bug:
It is possible for me to add 2 contacts with email addresses that differ only by Upper case and/or lowercase. however, this should not be possible, because in reality email addresses are case-insensitive. hence, it not possible for 2 contacts to have the same email address.
Steps to reproduce:
- enter
add n/John Doe p/98765432 e/johnd@example.com j/SWE2024 t/N r/part-time only into the command box.
- enter
add n/John Doe p/98765432 e/joHnd@example.com j/SWE2024 t/N r/part-time only into the command box.
Expected:
Throws an error message saying there is already a contact in the list with the same email address.
Actual:
Successfully adds both contacts into the contact list.
Screenshots:

Describe the bug:
It is possible for me to add 2 contacts with email addresses that differ only by Upper case and/or lowercase. however, this should not be possible, because in reality email addresses are case-insensitive. hence, it not possible for 2 contacts to have the same email address.
Steps to reproduce:
add n/John Doe p/98765432 e/johnd@example.com j/SWE2024 t/N r/part-time onlyinto the command box.add n/John Doe p/98765432 e/joHnd@example.com j/SWE2024 t/N r/part-time onlyinto the command box.Expected:
Throws an error message saying there is already a contact in the list with the same email address.
Actual:
Successfully adds both contacts into the contact list.
Screenshots:
