Oversized emails rejected but not logged

Nothing in the log?  What leads you to conclude that the emails reach the UTM at all?

Cheers - Bob

BAlfson said:

What leads you to conclude that the emails reach the UTM at all

The Non Delivery Report returned to the sender contains the following :

Action: failed
Status: 5.0.0
Remote-MTA: dns; [UTM_External_IP_Address]
Diagnostic-Code: smtp;cannot send to [UTM_External_IP_Address]: message is too large for the receiving server

In the smtp log downloaded from the UTM, the only trace I see that could be related to the message is a connection with our ISP relay that is opened then immediately closed :

• SMTP connection from [ISP_Relay_IP_Address]:37119 (TCP/IP connection count = 1)
• SMTP connection from [ISP_Relay_IP_Address]:37119 closed by QUIT

Thank you for your help BAlfson.

If a friend in France, monami@orange.fr, were to try to send me an email with a 60GB attachment, I would see the same thing in our logs.  In fact the orange.fr mail relay would close the connection immediately upon learning that our 'Max message size' is 50MB.  The conversation would look like the following with our Proxy's responses in red.

220 mxusa.mediasoft.com ESMTP ready.
EHLO orange.fr
250-mxusa.mediasoft.com Hello smtp.orange.fr [193.252.22.84]
250-SIZE 52428800
250-8BITMIME
250-PIPELINING
250-STARTTLS
250 HELP
QUIT

There is no further information sent by the orange.fr mail relay - no sender, no recipient, no subject, etc., so there's nothing more to log.

I'm curious to know what happens when you set the 'Max message size' to 999 to allow the UTM to accept a message larger than your mail server will accept.  When your server refuses to accept it from the UTM, will the UTM then bounce the message? (it might take two days)

Cheers - Bob

If a friend in France, monami@orange.fr, were to try to send me an email with a 60GB attachment, I would see the same thing in our logs.  In fact the orange.fr mail relay would close the connection immediately upon learning that our 'Max message size' is 50MB.  The conversation would look like the following with our Proxy's responses in red.

220 mxusa.mediasoft.com ESMTP ready.
EHLO orange.fr
250-mxusa.mediasoft.com Hello smtp.orange.fr [193.252.22.84]
250-SIZE 52428800
250-8BITMIME
250-PIPELINING
250-STARTTLS
250 HELP
QUIT

There is no further information sent by the orange.fr mail relay - no sender, no recipient, no subject, etc., so there's nothing more to log.

I'm curious to know what happens when you set the 'Max message size' to 999 to allow the UTM to accept a message larger than your mail server will accept.  When your server refuses to accept it from the UTM, will the UTM then bounce the message? (it might take two days)

Cheers - Bob

Thank you Bob,

I didn't know that the size limit was exposed as part of the EHLO response.

Now I know [:)].