Hi Nehme,
It's not officially documented, however OneSpan Sign internally utilizes "Apache Commons Validator 1.6" to validate user name, email address and email domain. If you check the source code for class org.apache.commons.validator.routines.EmailValidator.java, the username part has a length limitation of 64 characters.
Duo
Duo LiangOneSpan Evangelism and Partner Integrations Developer
Reply to: Signer Email Characters Limit
Tuesday, January 7, 2020 at 03:34amDuo Liang OneSpan Evangelism and Partner Integrations Developer