I also think it's standard IMAP...
Actually, I configured everything using MailStore's IMAP connection, but I'm still having problems...
Gabriele Maoret - Head of SysAdmins and CISO 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)