Hello,
When using Merak in DotNetPanel you may face with "Failed to save account" error when using "User Creation Wizard" to create a new hosting account and hosting space for it.
The source of this problem is that you probably use the same password for several accounts. When "Create Default 'Catch-All' Mail Account" is checked user creation wizard creates a new mailbox with mail@domain.com name and use the same password as specified for user account itself. Although, Merak allows creating mail accounts with the same name but on different domains, however it requires to have different passwords for that accounts (even on different mail domains!). Take a look at this Merak help-page: http://www.merakmailserver.com/Knowledgebase/Merak_Mail_Server/Accounts/Users.asp - it clearly states this fact.
So, our recommendation is to do not use the same password for user accounts when using "User Creation Wizard" with enabled "Create Default 'Catch-All' Mail Account" option.
Another tip might be helpful to your customers is that by default Merak web mail requires username and passwords to login. You may want to change this behaviour to accept full e-mail addresses and their passwords instead of usernames. To do this in the Merak Mail Server Administration go to "Merak Mail Server -> Domains & Accounts -> Policies -> Login Policy" Tab and change "Users login with their usernames" to "Users login with their email addresses".