The customer has an email with Single quote (') character and this is not accepted by Confluence when the user is added. But the same user can be added to Jira without any issue. 

For example test.emailD'Silva@abc.com

The customer has enabled SSO authentication and since the email ID doesn't match the username in confluence, the user is not authenticated. 

Expected Results

Confluence should accept a user name and email address with  Single quote (') 

Actual Results

Get an error Usernames cannot contain the characters '+', ',', '\', '<', '>', ', or ".