On Wed, 15 Oct 2014 22:12:41 +0100 Brad Rogers <[email protected]> wrote:
> On Wed, 15 Oct 2014 21:44:30 +0100 > Joe <[email protected]> wrote: > > Hello Joe, > > >It is *not* OK to silently delete an already accepted email, it does > > Unfortunately, it happens; Send an email with a large attachment(1) > and there are quite a few servers that will silently drop it. The > worst of it is you can never know for certain if you're going to get > "bitten" because routing can vary. > > (1) 4Meg or so used to do the trick. Things might be different now as > more and more messages contain massive amounts of HTML and imagery. > Possibly so, but in every case somebody has messed up. Firstly an MTA trying to send a large file should query whether the receiving server is happy with that. There will be receive limits on email size directly, but also the recipient's mailbox may not have enough spare space, and policy may be to refuse the large email rather than quarantine it somewhere else. If the receiving server isn't happy, the transaction is aborted and the sender told. If the sending server sends more than the receiver is happy with, even if no protest was raised earlier, or no warning of the size was given, the receiver can simply not acknowledge receipt, or indeed just terminate the TCP session, and again the sending server notifies the email sender, possibly after a couple of re-tries if it has not been explicitly told that the message isn't welcome. If a large email is accepted, but only later it is found that it cannot be delivered by reason of some policy, then it's up to the receiving server to tell the recipient. I'm not for a moment doubting that it happens as you say, but there's no need for it in the case of a legitimate email, it is always possible either for the receiving server to fail to complete the SMTP transaction, or for recipient-end processing to inform the recipient of any post-acceptance delivery problems. Either the sender or the recipient *can* be told. -- Joe -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected] Archive: https://lists.debian.org/[email protected]
