Add Mailbox setting wrong size

I have set up my server to allow 300 Mb in mailboxes. (I use IMAIL server)
 
When creating a mailbox, I get a CONFIGURE button. If I click on it I see a 50 Mb wich cannot be changed (a popup tells you to enter a number between 0 and 50).
 
The problem is that email accounts are being created with 50 Kb (not Mb)! 
And they should be created with 300 Mb. Please take into consideration that IMAIL uses bytes to specify sizes. If you put 51200 that is bytes, and equals 50Kb.
 
Can you please fix that? Thanks

HC control mailbox size via control panel, if you set by default in the mail server it may not work.

Here are the step to configure mailbox size in hc

1= Login in Hc as host go to ' Server Manager ----- Global Setting ---- Mail Server ---- Chose option " Configuration in Plan "

2= Same interface level (hcadmin ) go to Hosting Plan ---- Resource properties ---- Here Assign mailbox size to a reseller , by default it is 50 mb because of this reseller can't set more than 50 mb for mailbox, you can increase the number.

3= Now login in hc panel as reseller go to Hosting Plan---- My Plan ---- Edit Plan, from here you can set mailbox size as well as you can edit mail domain properties base on this plan setting.

Logged in as hcadmin, I cannot find that option in plan resources.
 
Under Mail Domains, I have:
Mail Server Type :
Mail Domains :
Mailboxes per Mail Domain :
Distribution Lists :
 
I don't have any mailbox size.
how can I get to that option?
 

At HCadmin level Don't edit the plan, look for icon " Plan resource properties " in Hosting Plan manager. And from there specify reseller mailbox quota.

Mailbox size will show after you login in reseller and press edit plan.

I have done everything. My plans as reseller show 300Mb.
When trying to add mailboxes, a 50 Mb maximum is enforced.
 
But thats not the only problem. even creating the mailbox with 50 Mb is interpreted by IMAIL as 50 Kb.
 
Can you please fix those 2 errors? thanks

Please contact HC support and open ticket with them they will debug this issue.
Open Ticket