Hi @senthil nathan ,
Does this only occur to this particular message which seems like an automatically generated mail by the system?
And do you mean when the same email account is configured in Outlook 2013, you are able to save the msg attachment of the same mail successfully?
I tried testing in my Outlook for Microsoft 365 and have no issue saving the attached .MSG file locally:
If you haven't checked other mails, could you try testing it further to eliminate if the issue is with the particular message generated by the mail delivery software?
Besides, instead of right-clicking the file and choosing "save as", it's suggested to try minimizing the Outlook window and directly dragging and dropping the msg attachment to desktop and see how it goes.
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