Many people want to use a mobile phone to send/receive their email nowadays. This is usually easy to do with VPOP3.
The recommended way is to have the phone connect directly to VPOP3 for sending/receiving email. To do this, you need to do three things:
You should also make sure that users have secure passwords.
Doing it this way means that you don't need to set up complex email forwardings and the possible complications that can result from that (message loops, duplicated messages, and incorrect reply addresses)
Many users want to go further, and have their phone email synchronise with their desktop email. This has the advantage that the phone can access all saved mail that the desktop can access - eg in other mail folders. Also, if a message is sent from the phone, it will appear in the 'Sent items' folder on the desktop (and vice versa). Deleting or moving a message on the phone will cause it to be deleted or moved on the desktop as well (and vice versa).
Doing this is wonderfully easy if you use VPOP3 Enterprise, and use IMAP for collecting your email on your phone and your desktop PC(s) - it will also synchronise between multiple PCs (eg at home and at the office). Once you have done this, you don't need to do anything fancy to synchronise the various email clients - the IMAP4 software will do it all for you.
Also, with VPOP3 Enterprise and IMAP4, the mobile phone email client will typically only download attachments if the user specifically requests them, otherwise it will just retrieve the message header list first of all, then the message text when the user views a message, so it will save a lot of time and bandwidth allowance rather than using POP3 collection, where the whole message has to be downloaded.