separate file directory dovecot / iredmail

Did you install the tutorial iredmail atravéz contained right here, but now a situation has arisen. I’ll need a lot of space to store files and email, but there is no possibility to increase only the size of disk space. I then thought about mounting a disc in my instance of S3, with only a directory for files and email. S3FS got to ride with, but to create the directory of email starts giving a lot of error in the dovecot log, because when using the vmail user, I believe that the Perm does not work, plus creates all files within the directory and -mail, no more proceeds with other creations and is in the LOG loop. Does anyone know an alternative to using a directory without space limitations in a digital instance of the ocean? Or operate this situation I set up using S3 and have dovecot / iredmail create files in that directory?