How to use WHMCS for selling mail-accounts on single domain?

[sushlik]

Hello,

I'd like to sell single mail-accounts to my clients on my own domain (e.g. "http://macbay.email/" )like this:

- client creates account with custom username@macbay.email
- client-account & billing (e.g. 12,- € for the upcoming 12 months) are being created on whmcs
- mail-account is being created on mail-server (e.g. cPanel or iredmail)

All WHMCS extensions that I have yet read about would allow me to sell hosting and domains, so that the client can setup multiple mail-accounts.

But I want to sell only single mail-accounts on my own domain with features like aliases (limited to 3 aliases per account), forwarders, sieve filters, identities (limited to 3 identities per account), fetchmail and the ability to extend mail-storage as config-option.

Any idea about how to accomplish? I would be willing to pay for someone to help me establish such a solution.

Thank you and kind regards,
Sascha