[Arne]

Hello out there,
My ISP recently changed it's mail protocol from POP to IMAP.
Since I am on the verge to buy a second computer (new one stationary and the old PowerBook for travelling), I am convinced that the advantages of IMAP over POP are significant enough for me to make the switch.
Since I am using the Mail application in OS X already, and since Mail is able to handle also IMAP, I thought changing the account(s) from POP to IMAP would be as easy as the click of the mouse in the Mail Preferences.
Unfortunately it is not.
Once chosen the Account Type in Mails Preferences, it is impossible to change it again. So, you cannot actually just swop the Account Type, but have to create a new account in Mail and transfer the old Inbox into the new one.
My questions now are: Am I thinking correctly, and how do I do this without losing all headers and flags from the messages?
Thanks for your input,
arne

[d00d]

Make the new account. Drag and drop the messages. All the data will be preserved as far as I know.

[Nobody]

I'm not really sure if I'm getting the idea of the topic. Here's what I could wring out from my brain. If your ISP changed the address of your Incoming Mail Server then you get that changed address from them in the support section. I'm almost sure they would provide such for the change over. Once you access that info, it is matter of deleting the old address in the Incoming Mail server data box. The User Name and Password data boxes could be updated if there were any changes depend on your ISP. That is your ISP needs you to change password and user name. So if that is not needed, you would not make new entries there. Easy as pie so far if the ISP provided the imap mail address.
The same goes fore the Outgoing Mail Server. You make the settings changes by opening up the popup Outgoing Mail Server options button next to Outgoing Mail Server (SMTP). A pane would have an options list: None, your present outgoing mail address, Add Server..., and Edit Server List.... Click on the option Add Server. Another pane would show up and you fill in the new data and select an option for Authentication which is probably a password. The port is automated and you have to check with the ISP about the SSL because if they don' use it, you won't get your mail. Leave it uncheck if the ISP don't use it. That's also true in the Advance mail options located in the main mail Accounts window next to the Mailboxes. That SSL option could cause you from not getting and sending your mail if that info is not squeezed out of your ISP.
The top section of the main Account Information where Description and Email Address is changed when it is needed if the ISP gives you new Email Address. Your name is changed if you had done that in the intermitten time your ISP made email changes. Just kidding. So now you launch your Mac mail and see if brings your email home. Hopefully I offered some help and your ISP provides the needed info.
In the Server Setting options button, once your Mac mail is abled to get your mail, click on the options button it would show your new IMAP mail settings.
The last thing you would want to do is delete the old mail settings by going back into the Outgoing Mail Server options button and select Edit Server List. Once the pane shows up, click on the old server and click on Remove Server then your done. The hard part of it all is getting the IMAP Mail Server Address from your ISP. Good Luck!

[Arne]

Thanks for your reply, teckman, but my question was more how I could preserve my old mails while changing from POP to IMAP. Derik hit the nail on the head...
Cheers,
arne

[Arne]

Of course, you were right.
Sometimes I forget that I sit in front of a Mac and don't need to worry so much about things ;-)
Thanks, Derik!
arne

[d00d]

No problem. I think you had a valid concern because one couldn't necessarily be sure that the data would be preserved. I think IMAP actually makes provisions in its protocol for all those things (flag/unread status). I think you'll be happy with IMAP. I know I was glad when I made the switch away from POP years ago. /forums/ubbthreads/images/graemlins/smile.gif

[Arne]

Thanks for the head-up, Derik.
I am now on IMAP 100% with all my 6 accounts (.mac being the only exception) for 3 hours and have the feeling (no prove) that the CPU load is slightly higher (talking about 3-5% more load on a 500Mhz TiPowerBook) than with POP.
Is it just my imagination or could it be technically proven?
Cheers,
arne

[d00d]

Hmm, not sure. I think it relies on several factors. One, if you synchronize all your mail folders, it's going to have to cache them the first time (though it should do that when you move your mail). If also uses some CPU to compare the cache with the server to make sure you're not out of sync. It's going to require more network resources as the mail data actually resides on the server instead of your computer's hard drive. That's my best guess as to why that's happening.

[Brettcamp]

Since we're on the subject, could you enumerate the advantages / disadvantages of using IMAP rather than POP? I think my university server allows IMAP, but the default is POP, and I hesitate to make a change without a good reason for doing so.

[d00d]

The single biggest advantage is that all your mail data and your organization structure (your folders) reside on the server. This means that you can set up any number of computers and IMAP mail clients to check your account without fear of deleting something off the server that you won't be able to access elsewhere. Likewise, all the changes you make are synchronized between every login location. This also makes it possible to have a webmail interface that respects the status of your filing.
Another advantage is that you can set an IMAP account to download the data of email messages only when specifically read. For instance, you're on the road using a dialup connection. You check your mail and someone you know has sent you several large (multiple megabyte) emails. With POP, you'd be downloading those messages. With IMAP, you could simply avoid them until you it's convenient (the same goes for filed mail).
So really, the main advantage is that the mail is stored server-side instead of local to a particular computer.