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"501 Error: attribute value too long" appears in Deep Discovery Email Inspector (DDEI)

    • Updated:
    • 5 Sep 2019
    • Product/Version:
    • Deep Discovery Email Inspector
    • Platform:
Summary

Emails are being rejected by DDEI with the following entry in mail log:

proxy-reject: END-OF-MESSAGE: 501 Error: attribute value too long; from=**FROM-ADDRESS** to=**TO-ADDRESS** proto=ESMTP helo=**MTA-HOSTNAME**

Details
Public

This issue is caused by an email not conforming to RFC:2821 by exceeding the maximum line length:

text line

 The maximum total length of a text line including the  is

 1000 characters (not counting the leading dot duplicated for

 transparency). This number may be increased by the use of SMTP

 Service Extensions.

This issue should be investigated on the upstream MTA, why it is sending non-RFC compliant emails to DDEI.

Premium
Internal
Rating:
Category:
Configure; Troubleshoot
Solution Id:
000146104
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