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It's likely worth noting that while they may resolve to the same point now, |
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there is nothing requiring the IMAP server (reading the mail stored on a |
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server) to match that is the SMTP server (outgoing mail). They are |
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entirely different purposes and protocols which do not need to live in the |
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same place. Makes perfect sense that they have different DNS names as they |
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may live on different endpoints at some point. |
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|
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This is one of the entire reasons we name things with DNS anyway. :) |
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On Oct 15, 2015 6:02 PM, "Mick" <michaelkintzios@×××××.com> wrote: |
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|
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> On Thursday 15 Oct 2015 18:04:22 walt wrote: |
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> > My ISP recently started offering imap email service in addition to |
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> > the pop3/smtp servers they've always had, so I decided to try it. |
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> > |
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> > I was surprised to see that they recommend using a different smtp |
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> > server name when setting up my mail client, and they even offer the |
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> > option of using port 587 instead of 465 if I prefer it. |
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> > |
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> > Why would I use a different smtp server if I'm now using imap? I use |
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> > smtp to send mail, and imap to read it, right? Why not use the same |
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> > smtp server in either case? |
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> > |
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> > (The different server names actually resolve to the same IP address, so |
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> > the distinction seems to be more theoretical than real, but the theory |
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> > is what puzzles me.) |
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> > |
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> > Thanks. |
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> |
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> Port 587 is for TLS and is the proper port to be used by MSAs as per |
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> RFC6409. |
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> |
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> Port 467 on the other hand is for SMTPS: vanilla SMTP at the application |
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> level, but the communication to the server is still secured at the |
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> transport |
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> layer with SSL. This was an IANA attempt to provide a port for secure |
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> email |
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> communication pre-STARTTLS days. Today I think may be used for other |
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> purposes, but I am not sure if it is TCP or UDP streaming. |
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> |
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> Port 25 (outgoing) is blocked by most domestic ISPs to guard against the |
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> millions of pawned botnets out there filling out inboxes with spam. |
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> |
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> The question about a different SMTP server might have something to do with |
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> your ISP adding a new SMTP mailserver to their farm and configuring it |
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> properly this time as per RFC6409. Although as Alan said, they probably |
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> rolled out whatever the chosen ISP package software vendor provided for |
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> them |
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> without knowing much about it, or why it is configured the way it is |
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> configured. |
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> |
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> -- |
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> Regards, |
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> Mick |
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> |