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emtunc
Asked: 2010-09-04 03:12:24 +0800 CST

Difference between POP3 (externally hosted) and Exchange (internally hosted)?

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Our set-up looks like this:

To receive email:

[[Our e-mail host]] --> POP3 [[Our Exchange 2003 server]]

To send e-mail:

[[Our Exchange 2003 server]] --> SMTP --> [[Zen internet]] --> [[[email protected]]]

Is the above set-up the way to go? Is it best practice to host your own exchange e-mail system? (we receive a lot of SPAM and many of the products only work when mail is retrieved via SMTP)

We are a small sized company of about 20-30 mailboxes - we use many of the Outlook 07/10 features such as meetings and calendars - I say this because I read that IMAP doesn't support this (I was looking at all possible options).

So my real questions are:

  1. So what are the main differences between POP3 and Exchange?

  2. Is it worth us switching over to Exchange hosted when we do an upgrade to SBS 2008?

  3. Apart from two (is that correct?) public IP addresses, is there any other 'special' requirements?

  4. Would it be safe to open up the Exchange server to the public internet? (of course, opening up anything to the outside world is dangerous, but will it be fine if set up properly?)

  5. Is there anything else I have not thought through properly? The main reason I want to do this is because I don't think that retrieving our e-mail via pop 3 from an external provider is how it's supposed to be done. Also, I do not believe we are making full use & flexibility of Exchange 2003's (or 2010 when we upgrade to SBS 2008) features by using POP3.

exchange-2003 exchange-2010 pop3

1 Answers

  1. Best Answer

    1. So what are the main differences between POP3 and Exchange?

    POP3 is a protocol, Exchange is an MTA, which can deliver mail using many protocols, it defaults to MAPI for user mail retrieval, but you can enable IMAP and POP3 (and even X.400) And it includes a webmail interface. (Which allows mobiles/iphones & remote users to access email). The webmail interface (when configured) allows users with broken Outlook to stay productive anywhere in the world.. ;-)

    2. Is it worth us switching over to Exchange hosted when we do an upgrade to SBS 2008?

    Unable to answer (No SBS experience) Don't know what you mean by hosted, you mean externally?

    3. Apart from two (is that correct?) public IP addresses, is there any other 'special' requirements?

    You only require one. Special? Active Directory is REQUIRED, as is a decent server with gobs of RAM and adequate backups. IIS is required for the web interface, as is SSL (so, either an external certificate or an internal CA)

    4. Would it be safe to open up the Exchange server to the public internet?

    If its behind a firewall, you should only need to expose certain functionality, like outbound SMTP from the exchange server, and inbound SMTP to the server, then if external users require access, I would make them use a VPN, or use HTTPS (Outlook can use RPC over HTTPS). To secure it more, pipe your messages through a filtering service, like MessageLabs.

    5. Is there anything else I have not thought through properly? I do not believe we are making full use & flexibility of Exchange by using POP3.

    No, no you aren't. By using MAPI internally, you keep the email on the server, and can back it up centrally, and can use public folders to share contacts/messages/todo/calendars etc with multiple users easily.

    I guess thats it, someone better can probably answer your questions more fully, and I look forward to reading their answers!

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