On Fri, 07 Aug 2015 18:53:49 +0200, "wilfried.es...@essignetz.de" <wilfried.es...@essignetz.de> wrote : > That makes me wonder. Do they know the difference between "envelope-to" > and "to"-field, or "envelope-from" and "from"-field? (This makes me > remember to the beginning of my fechmail era - they do not use fetchmail > or something similar?)
Good question, I do not know (and will have to wait for next Monday to ask). I assume they do this to protect against social engineering (I assume most MUA and users would mostly only pay attention to "From:" header), so filtering based on the header would make some sense - but I didn't check what envelope values are & their effect on rejection. > Usually smtp-Servers should only look to the the "envelope-to/-from", > which they exchange during the smtp dialogue. If a smtp-server is > checking only the from and to fields in the header of the received mail, > they will loose receipient information. That concerns not only mail from > lists, but also mail sent with adressess in BCC. > > Possibly, you should try to talk to this special admin. Looks like he's > violating some really important rfc's. This is my understanding of the issue so far, indeed. Regards, -- Vincent Pelletier ERP5 - open source ERP/CRM for flexible enterprises
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