If you get error from postfix mail log we have sollutions.
Error:
fatal: main.cf configuration error: mailbox_size_limit is smaller than message_size_limit
Show information about mailbox_size_limit and message_size_limit:
[root@email ~]# postconf -n | grep virtual_mailbox_limit
virtual_mailbox_limit = 51200000
[root@email ~]# postconf -n | grep message_size_limit
message_size_limit = 52928640
Now set a new value for virtual_mailbox_limit (bigger than message_size_limit) as follows:
postconf -e ‘virtual_mailbox_limit = 102400000’
(Replace 102400000 with a value of your choice.)
As an alternative, you can disable virtual_mailbox_limit by setting it to 0:
postconf -e ‘virtual_mailbox_limit = 0’
/etc/init.d/postfix restart