Login issue with AD

[m_alsoby]

hello

have an issue with login ID using AD

if any user has an email more than 20 characters before @ symbol. the characters will be removed.

for example " test_1234567890123456789@company.com "

the email owner will not be able to log in except if he type the first 20 characters "test_123456789012345"

any solution for this issue ?

thanks