none
5.5.3. Localpart too long..... after enabling SRS on forward RRS feed

  • Question

  • Hi,

    A relation of ours which forwards mails from booking sites has started to using SRS. This leads to email addresses where the local part exceeds 64 characters.
    Now the mails all bounce with the error message 5.5.3. Localpart too long.

    I tried to find where I can change a setting on Exchange that allows more characters so the bounce will not occur anymore. Unfortunately there's not much to find on this error.

    The guy who setup these forwards just tells me: "Change your mailserver settings".

    Yeah, but how?
    Can anyone help me on this one?
    Wednesday, August 30, 2017 7:20 AM

Answers

  • Tell your relation to stop doing that.  It's a violation of RFC 2821, which defines SMTP.

    https://www.ietf.org/rfc/rfc2821.txt

       local-part
          The maximum total length of a user name or other local-part is 64
          characters.

    The local-part is what's to the left of the @ symbol.

    What's SRS?


    Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."
    Celebrating 20 years of providing Exchange peer support!


    • Edited by Ed CrowleyMVP Thursday, August 31, 2017 4:28 AM
    • Proposed as answer by Allen_WangJF Thursday, August 31, 2017 11:32 AM
    • Marked as answer by BartVSA Thursday, August 31, 2017 12:21 PM
    Thursday, August 31, 2017 4:27 AM

All replies

  • Tell your relation to stop doing that.  It's a violation of RFC 2821, which defines SMTP.

    https://www.ietf.org/rfc/rfc2821.txt

       local-part
          The maximum total length of a user name or other local-part is 64
          characters.

    The local-part is what's to the left of the @ symbol.

    What's SRS?


    Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."
    Celebrating 20 years of providing Exchange peer support!


    • Edited by Ed CrowleyMVP Thursday, August 31, 2017 4:28 AM
    • Proposed as answer by Allen_WangJF Thursday, August 31, 2017 11:32 AM
    • Marked as answer by BartVSA Thursday, August 31, 2017 12:21 PM
    Thursday, August 31, 2017 4:27 AM
  • Agree with Ed.

    Moreover, get more information about , please refer to: Unsupported Characters for Exchange 2010 Object Names.


    Regards,

    Allen Wang


    Please remember to mark the replies as answers if they help and unmark them if they provide no help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Thursday, August 31, 2017 11:34 AM
  • Hi Ed,

    Thanks for your reply. The RFC for me is enough to bounce this "problem" back to him.

    SRS seems to be a "fix" for broken email-forwards.... http://www.openspf.org/SRS

    Thursday, August 31, 2017 12:21 PM