Problems with Accessing Multiple Email Accounts/Addresses/Mailboxes
As mention previously there are two ways of accessing email accounts from a single
interface (email client like Outlook):
- Access multiple accounts directly from the Client
- Have the email forwarded to a main account
Note: An Email account is a combination of mailbox and
address.
When using POP3 as the access protocol clients like Outlook Express, Outlook etc place the email in a single
inbox; so called universal mailbox.
Here is my Outlook service screen which show that I am accessing
3 different email accounts.

The exact setup is dependent on the particular email client but
in general they are very similar as the same information is required
by each client.
Here is how to configure both Outlook Express and IncrediMail:
Sending and Replying To Emails
This is really where you encounter problems with having multiple accounts.
There are two cases for sending:
- Sending in response to an email - Reply
- Sending a new email
Replying to an email works well, as the reply address is the
original recipient address. That is if the original email was sent
to address A when you respond by replying the sender address is set
to Address A, which is what you want.
The real problem comes with sending a new email. In this case the
sender address is set to the primary email address but you can
change it.
When sending from most clients that are configured to use
multiple accounts you will see the from line. You can use
this line to set the address to whichever account you want the
mail to be sent from. (screenshot below)

Organizing Emails From Different Accounts
Even though the Universal inbox is a great idea many want to know which email was sent to which email address, and so we need any easy way of flagging the email.
The easiest way of doing this is by using message rules. It is possible to configure a message rule that will move all email sent to address A to folder A and even to highlight it with a different
colour.
Here are the message rules for both IncrediMail:

and Outlook Express:

If you are unsure of how to configure message rules see:
Problems Arising from Email Forwarding
Another way of getting mail from multiple accounts into a single mailbox is to use the technique of email forwarding.
If email for mailbox B is forwarded to Mailbox A then there is no way of sending
email in response with Mailbox as the sender. The sender will always be mailbox
A.
It is for this reason that I prefer to only forward messages for read only
purposes.
Using IMAP4 and/or Multiple Email Clients
Instead of configuring a single email client to handle multiple
accounts it is possible to use different clients.-
Using Multiple Email Clients
. However by far the best solution os to use IMAP4 as the access
protocol, as it keeps the inboxes separate by default.
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