We host a domain on sonic.net, which I manage. Let's call it someco.biz.
For many email accounts in the domain, I simply forward the user's someco.biz to another email account that they have. No problems there.
Some other users, however, prefer to have their email client software get email from the someco.biz/sonic server. For these users, I created a separate, "native" sonic.net address and forward the mails to that. E.g.:
firstname.lastname@example.org forwards to email@example.com
I did it that way because sonic doesn't provide a more direct method to store email for domain addresses, and
someone at sonic.net suggested this indirect approach.
This indirect approach works, but it's not at all intuitive for users who want to access email via sonic webmail or who want to configure their autoresponse messages. They have to (1) remember to go to sonic.net to login, and (2) remember a login name that's different from their someco.biz user name (e.g., ww_hiram instead of hiram). Users often forget or get confused and have to ask me for the procedure and for their login credentials.
The indirection also makes initial configuration of the user's email client unnecessarily confusing/unintuitive.
There should be a way to configure the domain so that users can login directly to someco.biz for webmail and email account configuration (especially autoresponse message) and use someco.biz server and user names for email client configuration. Most other web hosts that I've used has this capability.