Guru-host offer various packages based on Zimbra. You can however create your own package in case that any of the packages below does not cover your needs. Just contact us and we will create the package for you within the day. All our packages include free of charge a secondary MX record[1] ensuring that you wont loose any email even in case of primary server goes down.
Except the above packages you can have "unlimited" mailboxes by ordering a dedicated server and have us install and configure the Zimbra Suite on your server. You will need to contact us to get a quote as implementation varies depending the scenarios.
[1] A mail exchanger record (MX record) is a type of resource record in the Domain Name System that specifies a mail server responsible for accepting email messages on behalf of a recipient's domain and a preference value used to prioritize mail delivery if multiple mail servers are available. The set of MX records of a domain name specifies how email should be routed with the Simple Mail Transfer Protocol.
A target server, i.e. one that knows how to deliver to the relevant user's e-mail mailbox is typically one which is the most preferred. Lower priority servers, a.k.a. backup MX or secondary MX, usually keep the messages in a queue waiting for the primary server to become available. If both servers are online or in some way connected to one another, the backup MX will typically queue a message briefly and immediately forward it to the primary MX. The backup MX acts as a store-and-forward mail server.
