You see a large number of abort message entries coming from Gmail email addresses.
Article ID: 162267
When looking at the Message Audit Log at emails from gmail.com email addresses, you notice a lot of abort message entries.
As evidenced by recent packet captures for customer seeing this issue, Google tries to send a large email despite the size specification being provided in the ESMTP response. Here is an example:
220 smtp01.x.com ESMTP Symantec Messaging Gateway EHLO mail-xxx.google.com 250-smtp01.x.com says EHLO to 209.x.x.x:34896 250-ENHANCEDSTATUSCODES 250-SIZE 15485760 250-8BITMIME 250 PIPELINING MAIL FROM:<[email protected]> SIZE=24814870 552 5.3.4 message size limit exceeded at MAIL FROM RCPT TO:<[email protected]> 503 5.5.1 RCPT TO without MAIL FROM DATA 503 5.5.1 DATA without MAIL FROM QUIT 221 2.3.0 smtp01.x.com closing connection
The above communication showed as an abort message.
This issue is outside the Messaging Gateway, Google's MTA is not correctly reading the SIZE parameter.