LDAP Users not recognized through email integration

Hello friends,
I have a problem, it happens that when tickets are generated by sending emails, these tickets have as the user the X500 address of the email account, attached a photo, the sysaid support indicates that the user is not in the GAL, but I confirm with the email support of my company, and they tell me that the account that presents this problem is in the GAL, someone who can help me with this please thabks