entire attachment is received before being reject on size

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porcupine
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entire attachment is received before being reject on size

Post by porcupine » 2007-03-22 09:28

This doesn't seem to have been discussed before.

When sending a message via smtp with an attachment that exceeds the allowed maximum, the DATA session completes before being rejected, therefore if the attachment is 50MB and the max allowed is 20MB, you wasted an additional 30MB of bandwidth to find out it should be rejected. This was especially painful when one idiot was sending 150MB and his mail client retried 20 times during the week.

is this expected behaviour or should the message be rejected when the DATA session hits 20MB, we have many remote users and I know I would prefer the message to be rejected as soon as the limit is hit, not wait for the entire DATA to be received.

4.3-B248 MySQL

^DooM^
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Post by ^DooM^ » 2007-03-22 10:55

I am not sure but I would presume this would go against some RFC about breaking a connection. I am pretty sure that when a client is sending data it is not listening for abort commands or similar. Hmail would just have to drop the connection.

That's my take on it any way, Martin would know better how it works.

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martin
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Post by martin » 2007-03-22 13:06

^DooM^ is right, there's no support for that in the RFC. If hMailServer would just drop the connection, there wouldn't be any way for the user to know what went wrong, and he would probably contact the server administrator.

Modern email clients normally tells the receiving server the size of the message before it starts to send it. If it does, hMailServer will reject it before the delivery is started if it's to big.

porcupine
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Post by porcupine » 2007-03-22 13:46

many thanks for the RFC clarification and for the note on client apps...

sad to say Outlook 2003 SP2 does not provide the DATA size prior to sending (and thats with no AV interference/proxying)

Edit:
And you guessed it.... Thunderbird sends the DATA size before transmitting, hMailServer rejects the message accordingly

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Post by ^DooM^ » 2007-03-22 17:10

Go Microsoft !!!!!! :P

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