POP Account

This is important to make the distinction between email accounts and mail aliases.
Providing multiple email addresses in an account configuration lets you choose what alias you want to use when sending specific emails. But there is one POP/IMAP account associated with it.
However, you can create rules to move messages to specific folders when they are fetched from the server, automatically, according to the "To:" field of the message.
This is in Preferences/Rules settings

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Why reward points ?

Normally you need to set up an account for each address in the e-mail program, one account for one address and another account for another address.

Generally for a pop account to be used on your computer e-mail program you will need:

e-mail address (e.g. you@somedomain.com)
username (e.g. could be: you or you@somedomain.com or something else)
password (Your e-mail account password)
pop (e.g. could be: pop.somedomain.com, mail.somedomain.com or something else)
smtp (e.g. could be: smtp.somedomain.com, mail.somedomain.com or something else)

Generally the first 3 items on the list above will be different, if the addresses are with the same company/domain/isp then the pop and smtp will more than likly be the same.

With some accounts types you will need to have 'Anthenticate' selected, gennerally by password.

Hope this helps.

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Please see the "helpful" and "solved" button's on top off this message.

Are these email accounts provided by your ISP separate accounts?

What I mean by separate accounts - does each account or email address have its own user name or do you have a primary email account and additional email addresses or what is called an "alias" account or address to the primary account which shares the same user name and password as the primary account?

An "alias" accounts shares the same incoming mail server, user name and password as the primary account.

A separate account has its own user name which is usually the portion of the email address in front of the @ sign only but with some providers it is the entire email address.

Who is your new ISP?

It is important to determine for certain if the additional account is a separate account or an alias to the primary account.

When creating the other account/email address, did you provide a different password?

If the additional account/address is an alias to the primary account which shares the same user name and password as the primary account, the way you set up the account and the alias in Mail should work.

You're welcome.

By old accounts do you mean the accounts provided by your former ISP?

If you have cancelled service with your former ISP, weren't the email accounts provided by your former ISP cancelled also?

If you haven't cancelled service with your former ISP or your account will remain active until the end of this month, you can create the email accounts provided by your former ISP in Mail also which should be in the same way as you created the accounts provided by your new ISP - as a separate account for each email address.