Keys not trusted

[Wolfgang Bornath]

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Hi,

Being fairly new in this I joined this list and received some messages=20
by people who signed their messages. I always imported the keys (using=20
the gpg option --auto-key-retrieve) and kmail tells me
"Message is signed by XY (blahblub) (Key-ID: 0x12345678).
Signature is valid but the key is not trusted."

When I want to send a private mail to somebody like that and I want to=20
encrypt the text I see the list of my pubring but all imported keys are=20
marked red and I cannot encrypt.
Only my own public key is marked green and I can use it to send=20
encrypted mails to myself (Big Deal!)
I signed one of those public keys because I know the person and my sig=20
is listed but still the same.

Could someone explain or point me into the right direction?

wobo
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Public GnuPG key available at keyserver pgp.mit.edu
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