I wonder if anyone can shed any light on this seemingly strange "feature"?
We have recently started receiving spam emails through to various users where the email address is prepended with a pipe character (|), eg:
Because of this character the messages are being allowed through our 3rd party spam filter as it doesn't match it to the list of protected addresses, however my main question is how these emails are actually getting to the users when the addresses (including the pipe) do not actually exist??
We have tested this a bit and have found that if we try and send an internal email from Outlook and include the pipe character we get an undeliverable error. However if we send one from an external account (eg my Google Mail account) it comes through fine.
FYI, when the emails are received the pipe character is still included in the smtp address of the recipient. I thought they might be being recognised as just a delimiter between addresses, like a semi-colon, but that doesn't appear to be the case.
Can anyone explain how/why this is happening? I assume Exchange server is interpreting the pipe in some weird way? Is this a bug or by design?
--James
We have recently started receiving spam emails through to various users where the email address is prepended with a pipe character (|), eg:
Code:
|my.user@myco.comBecause of this character the messages are being allowed through our 3rd party spam filter as it doesn't match it to the list of protected addresses, however my main question is how these emails are actually getting to the users when the addresses (including the pipe) do not actually exist??
We have tested this a bit and have found that if we try and send an internal email from Outlook and include the pipe character we get an undeliverable error. However if we send one from an external account (eg my Google Mail account) it comes through fine.
FYI, when the emails are received the pipe character is still included in the smtp address of the recipient. I thought they might be being recognised as just a delimiter between addresses, like a semi-colon, but that doesn't appear to be the case.
Can anyone explain how/why this is happening? I assume Exchange server is interpreting the pipe in some weird way? Is this a bug or by design?
--James
