Do you see the received mail in the webmail?
If not, look up what happens to your received mail message in the DELIVERY log.
The SMTP log occurs when the server receives mail from outside and then queues it for subsequent delivery, the DELIVERY log indicates what happens when the queued mail is to be delivered to the destination recipient.
Gabriele Maoret - Head of SysAdmins at SERSIS
Currently manages 6 SmarterMail installations (1 in the cloud for SERSIS which provides services to a few hundred third-party email domains + 5 on-premise for customers who prefer to have their mail server in-house)