[X-Unix] CL Usenet and email

[William H. Magill]

On 16 Apr, 2005, at 17:34, James Bucanek wrote:
> Jamie Kahn Genet wrote on Sunday, April 17, 2005:
>> James Bucanek <subscriber at gloaming.com> wrote:
>>> Went to IMAP years ago.  Ran away screaming and cursing.  Will 
>>> probably
>>> never go back.
>>
>> Why exactly, if you don't mind me asking?
>
> For my needs, it simply adds a useless layer of complexity to getting 
> my mail.  Mainly, it's just dreadfully slow.  Even with a cable modem 
> Internet connection, just opening my mail app was painful because it 
> would have to re-sync with 100+ mailboxes.  Reading a hundred local 
> files is orders of magnitude faster.
>
> It was also a dog getting mail.  To apply any kind of complex 
> filtering, every message still had to be downloaded to my local 
> client, which would then have to send command back to the server to 
> move the message around.  A POP client just gets the messages and does 
> something with it (locally).  Much faster.  So IMAP actually created 
> more Internet traffic than POP.
>
> If I want to run a script (like my mail archiving script) or 
> re-process mail, often it had to be read (again) from the server, then 
> more interminably slow IMAP commands have to sent back to the server 
> to update the mailbox.  It's not like it didn't work, but the exact 
> same procedure on local mailbox files are about a thousand times 
> faster.  And, I don't have to be connected to the Internet to use 
> them.
>
> I admit where IMAP can be really useful for someone who accesses their 
> mail from multiple locations (like a home and work computer).  And if 
> I were in that situation, I might consider setting up an IMAP account 
> to do that.  But outside of that advantage, IMAP simply takes 
> everything that a good POP client can do and gets in the way.

That's the entire difference between POP and IMAP.

The POP protocol was designed to download all your mail to your desktop 
each time you connect to the server and not leave any messages behind 
on the server. The primary assumption made by the POP protocol is that 
you will always read mail from only one location. Using the "Leave mail 
on server" option impacts POP even more than it does IMAP ... because 
you have to down-load ALL your messages every time. [It also becomes 
much more of a security issue if you use public clients.] That's slow 
enough with 10 or 20 messages, but as you get to several hundred, it 
gets painful. Plus the fact that most pop clients tend to barf as the 
number of messages being processed (even locally) approaches a couple 
of thousand... but that's a client problem, not an issue with the 
protocol. The POP protocol is not designed to support either multiple 
locations, or extensive "archiving" on the server.

The IMAP protocol was designed to leave the mail on the server so that 
mail could be read from multiple locations and only download the 
message headers to a client until a message is selected to be read. The 
premise being that your mail processing would be done on the server.

The tradeoff is as you describe it -- local processing is faster, but 
you must always access your mail from only one location, or be willing 
to risk loosing mail you have downloaded to the "wrong machine."

If you have 150 mail boxes with thousands of messages (as I do) POP is 
simply not a reasonable alternative unless you are willing to stick 
bigger disk drives on your "desktop" machine instead of your mail 
server ... or not archive anything "on-line." In my case, my IMAP 
server is on my local network and accessing it takes place at 100 meg 
speed.

Granted, if you are using some remote ISP's mail server, setting up a 
local mail server is a bit of effort. In that case, POP is also 
preferred in that you don't have to worry about your mail sitting 
around on your ISP's backup tapes. (Assuming that you are paranoid 
about such things in the first place.)

BTW, don't forget most Cable Modem connections are only 1.5 meg or 
maybe 3 meg in speed. They may clock at 10 meg, but that's not their 
throughput speed. They are actively limited. For example, several 
different services in this area (Philadelphia) charge different rates 
for "residential" - 1.5 meg; "gaming" - 3 meg; and "business" 3-5 meg. 
I'm not aware of any local cable provider who will "guarantee" 10 meg 
throughput, even for their business service.

T.T.F.N.
William H. Magill
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