Webmail vs. Sending mail with IMAP
 

I have a client that wants easy access to their email from anywhere. I am looking for a webmail type app or software that is accessible from anywhere - which they can use with their own domain name and with a great GUI. They can pay so free/paid is not an issue.

I use HORDE - but my client doesn't like it. This is mostly because of aesthetic reasons ie. viewing HTML is a click away, can't use images in your sig etc They are used to Outlook or Eudora with the fancy GUI and bell-and-whistle features.

I haven't done so myself in a long time - but can't I also send mail through IMAP? Like they can just use Outlook or Eudora on their office machine and their laptop? but:

If you leave your outgoing mail set to your mail server aren't there issues with outgoing mail when you are working remotely? Do you have to change your "Outgoing email" settings every time you travel?

Just trying to figure it out ? any help would be appreciated. :helpme

Thanks GFY.