Zitat von Christine Karman <christine(a)christine.nl>nl>:
Not sure what you mean with opaque signed though...
There are two ways of signing
data. One way signs the data and puts a
blob underneath, leaving the data readable. The other way, opaque
signing, renders the data unreadable.
Some mail servers decide that the formatting of a signed message is not
correct, and they change it, rendering the signature invalid. Opaque
signing prevents that.
Thanks for the explanation, until now i was biased to Thunderbird
S/MIME which only do clear-text signing as far as i know. The real
solution for us (and others with non S/MIME backend) is to remove the
signature at the gateway level as it can't verify anyway.